Optimize dartium dart:html bindings so real world application performance is acceptable. Improves dart:html performance by 2X-30X for microbenchmarks. Real world improvement is typically 2X-3X.

BUG=

Review URL: https://codereview.chromium.org/1832713002 .

sdk/lib/html/dart2js/html_dart2js.dart

@@ -123,9 +123,6 @@ Future<Isolate> spawnDomUri(Uri uri, List<String> args, message) {
   throw new UnimplementedError();
 }
 
-/// Dartium functions that are a NOOP in dart2js.
-unwrap_jso(dartClass_instance) => dartClass_instance;
-wrap_jso(jsObject) => jsObject;
 createCustomUpgrader(Type customElementClass, $this) => $this;
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a

sdk/lib/html/html_common/conversions_dart2js.dart

@@ -91,9 +91,3 @@ Future convertNativePromiseToDartFuture(promise) {
   var newPromise = JS('', '#.then(#)["catch"](#)', promise, then, error);
   return completer.future;
 }
-
-/// Wrap a JS object with an instance of the matching dart:html class. Used only in Dartium.
-wrap_jso(jsObject) => jsObject;
-
-/// Find the underlying JS object for a dart:html Dart object.
-unwrap_jso(dartClass_instance) => dartClass_instance;

sdk/lib/html/html_common/conversions_dartium.dart

@@ -7,11 +7,11 @@ convertNativeToDart_AcceptStructuredClone(object, {mustCopy: false}) =>
     new _AcceptStructuredCloneDartium().convertNativeToDart_AcceptStructuredClone(object, mustCopy: mustCopy);
 
 class _StructuredCloneDartium extends _StructuredClone {
-  newJsMap() => new js.JsObject(js.context["Object"]);
+  newJsMap() => js.JsNative.newObject();
-  putIntoMap(map, key, value) => map[key] = value;
+  putIntoMap(map, key, value) => js.JsNative.setProperty(map, key, value);
-  // TODO(alanknight): Don't create two extra lists to get a fixed-length JS list.
+  newJsList(length) => js.JsNative.newArray()..length = length;
-  newJsList(length) => new js.JsArray.from(new List(length));
+  cloneNotRequired(e) =>
-  cloneNotRequired(e) => e is js.JsObject;
+      e is js.JSObject || e is TypedData || e is ByteBuffer;
 }
 
 /// A version of _AcceptStructuredClone, but using a different algorithm
@@ -24,15 +24,14 @@ class _StructuredCloneDartium extends _StructuredClone {
 class _AcceptStructuredCloneDartium {
   newDartList(length) => new List(length);
 
-  // JsObjects won't be identical, but will be equal only if the underlying
+  // As long as we stick to JSObject instead of intermingling legacy JsObject,
-  // Js entities are identical.
+  // we can simply use identical.
-  bool identicalInJs(a, b) =>
+  bool identicalInJs(a, b) => identical(a, b);
-      (a is js.JsObject) ? a == b : identical(a, b);
 
   void forEachJsField(jsObject, action) {
-    var keys = js.context["Object"].callMethod("keys", [jsObject]);
+    var keys = js.JsNative.callMethod(_object, "keys", [jsObject]);
     for (var key in keys) {
-      action(key, jsObject[key]);
+      action(key, js.JsNative.getProperty(jsObject, key));
     }
   }
 
@@ -52,10 +51,7 @@ class _AcceptStructuredCloneDartium {
     if (e is bool) return e;
     if (e is num) return e;
     if (e is String) return e;
-
+    if (e is DateTime) return e;
-    if (isJavaScriptDate(e)) {
-      return convertNativeToDart_DateTime(e);
-    }
 
     if (isJavaScriptRegExp(e)) {
       // TODO(sra).
@@ -106,51 +102,60 @@ class _AcceptStructuredCloneDartium {
   }
 }
 
-final _dateConstructor = js.context["Date"];
+final _dateConstructor = js.JsNative.getProperty(window, "Date");
-final _regexConstructor = js.context["RegExp"];
+final _regexConstructor = js.JsNative.getProperty(window, "RegExp");
 
-bool isJavaScriptDate(value) => value is js.JsObject && value.instanceof(_dateConstructor);
+bool isJavaScriptDate(value) => value is js.JSObject && js.JsNative.instanceof(value, _dateConstructor);
-bool isJavaScriptRegExp(value) => value is js.JsObject && value.instanceof(_regexConstructor);
+bool isJavaScriptRegExp(value) => value is js.JSObject && js.JsNative.instanceof(value, _regexConstructor);
-bool isJavaScriptArray(value) => value is js.JsArray;
+bool isJavaScriptArray(value) => value is js.JSArray;
 
-final _object = js.context["Object"];
+final _object = js.JsNative.getProperty(window, "Object");
-final _getPrototypeOf = _object["getPrototypeOf"];
+final _getPrototypeOf = js.JsNative.getProperty(_object, "getPrototypeOf");
 _getProto(object) {
-  return _getPrototypeOf.apply([object]);
+  return _getPrototypeOf(object);
 }
-final _objectProto = js.context["Object"]["prototype"];
+final _objectProto = js.JsNative.getProperty(_object, "prototype");
 
 bool isJavaScriptSimpleObject(value) {
-  if (value is! js.JsObject) return false;
+  if (value is! js.JSObject) return false;
   var proto = _getProto(value);
   return proto == _objectProto || proto == null;
 }
+
+// TODO(jacobr): this makes little sense unless we are doing something
+// ambitious to make Dartium and Dart2Js interop well with each other.
 bool isImmutableJavaScriptArray(value) =>
-    isJavaScriptArray(value) && value["immutable$list"] != null;
+    isJavaScriptArray(value) && js.JsNative.getProperty(value, "immutable$list") != null;
 
-final _promiseConstructor = js.context['Promise'];
+final _promiseConstructor = js.JsNative.getProperty(window, 'Promise');
-bool isJavaScriptPromise(value) => value is js.JsObject && value['constructor'] == _promiseConstructor;
+bool isJavaScriptPromise(value) => value is js.JSObject && identical(js.JsNative.getProperty(value, 'constructor'), _promiseConstructor);
 
-Future convertNativePromiseToDartFuture(js.JsObject promise) {
+Future convertNativePromiseToDartFuture(js.JSObject promise) {
   var completer = new Completer();
-  var newPromise = promise
+  var newPromise = js.JsNative.callMethod(js.JsNative.callMethod(promise,
-    .callMethod("then", [(result) => completer.complete(result)])
+    "then", [js.allowInterop((result) => completer.complete(result))]),
-    .callMethod("catch", [(result) => completer.completeError(result)]);
+    "catch", [js.allowInterop((result) => completer.completeError(result))]);
   return completer.future;
 }
 
 convertDartToNative_DateTime(DateTime date) {
-  return new js.JsObject(js.context["Date"], [date.millisecondsSinceEpoch]);
+  return date;
 }
 
 /// Creates a Dart Rectangle from a Javascript object with properties
-/// left, top, width and height. Used internally in Dartium.
+/// left, top, width and height or a 4 element array of integers. Used internally in Dartium.
-Rectangle make_dart_rectangle(r) =>
+Rectangle make_dart_rectangle(r) {
-    r == null ? null : new Rectangle(
+  if (r == null) return null;
-    js.JsNative.getProperty(r, 'left'),
+  if (r is List) {
-    js.JsNative.getProperty(r, 'top'),
+    return new Rectangle(r[0], r[1], r[2], r[3]);
-    js.JsNative.getProperty(r, 'width'),
+  }
-    js.JsNative.getProperty(r, 'height'));
+
+  return new Rectangle(
+      js.JsNative.getProperty(r, 'left'),
+      js.JsNative.getProperty(r, 'top'),
+      js.JsNative.getProperty(r, 'width'),
+      js.JsNative.getProperty(r, 'height'));
+}
 
 // Converts a flat Dart map into a JavaScript object with properties this is
 // is the Dartium only version it uses dart:js.
@@ -158,16 +163,16 @@ Rectangle make_dart_rectangle(r) =>
 // code in html_common and be more general.
 convertDartToNative_Dictionary(Map dict) {
   if (dict == null) return null;
-  var jsObject = new js.JsObject(js.JsNative.getProperty(js.context, 'Object'));
+  var jsObject = js.JsNative.newObject();
   dict.forEach((String key, value) {
     if (value is List) {
-      var jsArray = new js.JsArray();
+      var jsArray = js.JsNative.newArray();
       value.forEach((elem) {
         jsArray.add(elem is Map ? convertDartToNative_Dictionary(elem): elem);
       });
-      jsObject[key] = jsArray;
+      js.JsNative.setProperty(jsObject, key, jsArray);
     } else {
-      jsObject[key] = value;
+      js.JsNative.setProperty(jsObject, key, value);
     }
   });
   return jsObject;
@@ -196,8 +201,15 @@ class _ReturnedDictionary {
 
 // Helper function to wrapped a returned dictionary from blink to a Dart looking
 // class.
-convertNativeDictionaryToDartDictionary(Map values) =>
+convertNativeDictionaryToDartDictionary(values) {
-  values != null ? new _ReturnedDictionary(values) : null;
+  if (values is! Map) {
+    // TODO(jacobr): wish wwe didn't have to do this.
+    values = convertNativeToDart_SerializedScriptValue(values);
+  }
+  return values != null ? new _ReturnedDictionary(values) : null;
+}
+
+convertNativeToDart_Dictionary(values) => convertNativeToDart_SerializedScriptValue(values);
 
 // Conversion function place holder (currently not used in dart2js or dartium).
 List convertDartToNative_StringArray(List<String> input) => input;
@@ -205,284 +217,59 @@ List convertDartToNative_StringArray(List<String> input) => input;
 // Converts a Dart list into a JsArray. For the Dartium version only.
 convertDartToNative_List(List input) => new js.JsArray()..addAll(input);
 
-/// Find the underlying JS object for a dart:html Dart object.
+// Incredibly slow implementation to lookup the runtime type for an object.
-unwrap_jso(dartClass_instance) => js.unwrap_jso(dartClass_instance);
+// Fortunately, performance doesn't matter much as the results are cached
-
+// as long as the object being looked up has a valid prototype.
-// Flag to disable JS interop asserts.  Setting to false will speed up the
+// TODO(jacobr): we should track the # of lookups to ensure that things aren't
-// wrap_jso calls.
+// going off the rails due to objects with null prototypes, etc.
-bool interop_checks = false;
+// Note: unlike all other methods in this class, here we intentionally use
-
+// the old JsObject types to bootstrap the new typed bindings.
-/// Wrap a JS object with an instance of the matching dart:html class. Used only in Dartium.
+Type lookupType(js.JsObject jsObject, bool isElement) {
-wrap_jso(jsObject) {
   try {
-    if (jsObject is! js.JsObject || jsObject == null) {
+  // TODO(jacobr): add static methods that return the runtime type of the patch
-      // JS Interop converted the object to a Dart class e.g., Uint8ClampedList.
+  // class so that this code works as expected.
-      // or it's a simple type.
+  if (jsObject is js.JsArray) {
-      return jsObject;
+    return js.JSArray.instanceRuntimeType;
-    }
+  }
-
+  if (jsObject is js.JsFunction) {
-    var wrapper = js.getDartHtmlWrapperFor(jsObject);
+    return js.JSFunction.instanceRuntimeType;
-    // if we have a wrapper return the Dart instance.
+  }
-    if (wrapper != null) {
-      return wrapper;
-    }
-
-    if (jsObject is js.JsArray) {
-      wrapper = new js.JSArray.create(jsObject);
-      js.setDartHtmlWrapperFor(jsObject, wrapper);
-      return wrapper;
-    }
-    if (jsObject is js.JsFunction) {
-      wrapper = new js.JSFunction.create(jsObject);
-      js.setDartHtmlWrapperFor(jsObject, wrapper);
-      return wrapper;
-    }
-
-    // Try the most general type conversions on it.
-    // TODO(alanknight): We may be able to do better. This maintains identity,
-    // which is useful, but expensive. And if we nest something that only
-    // this conversion handles, how does that work? e.g. a list of maps of elements.
-    var converted = convertNativeToDart_SerializedScriptValue(jsObject);
-    if (!identical(converted, jsObject)) {
-      return converted;
-    }
 
     var constructor = js.JsNative.getProperty(jsObject, 'constructor');
     if (constructor == null) {
       // Perfectly valid case for JavaScript objects where __proto__ has
       // intentionally been set to null.
-      js.setDartHtmlWrapperFor(jsObject, new js.JSObject.create(jsObject));
+      // We should track and warn about this case as peformance will be poor.
-      return jsObject;
+      return js.JSObject.instanceRuntimeType;
     }
     var jsTypeName = js.JsNative.getProperty(constructor, 'name');
     if (jsTypeName is! String || jsTypeName.length == 0) {
       // Not an html type.
-      wrapper = new js.JSObject.create(jsObject);
+      return js.JSObject.instanceRuntimeType;
-      js.setDartHtmlWrapperFor(jsObject, wrapper);
-      return wrapper;
     }
 
     var dartClass_instance;
     var customElementClass = null;
-    var extendsTag = "";
+    var extendsTag = "";    
-    var custom = getCustomElementEntry(jsObject);
-    if (custom != null) {
-      customElementClass = custom['type'];
-      extendsTag = custom['extends'];
-    }
 
-    // Only allow custom elements to be created in the html or svg default
+    Type type = getHtmlCreateType(jsTypeName);
-    // namespace.
+    if (type != null) return type;
-    var func;
+
-    var defaultNS = jsObject['namespaceURI'] == 'http://www.w3.org/1999/xhtml' ||
+    // Start walking the prototype chain looking for a JS class.
-        jsObject['namespaceURI'] ==  'http://www.w3.org/2000/svg';
+    var prototype = js.JsNative.getProperty(jsObject, '__proto__');
-    if (customElementClass != null && extendsTag == "" && defaultNS) {
+    while (prototype != null) {
-      // The customElementClass is known but we can't create the real class so
+      // We're a Dart class that's pointing to a JS class.
-      // create the HtmlElement and it will get upgraded when registerElement's
+      var constructor = js.JsNative.getProperty(prototype, 'constructor');
-      // createdCallback is called.
+      if (constructor != null) {          
-      func = getHtmlCreateFunction('HTMLElement');
+        jsTypeName = js.JsNative.getProperty(constructor, 'name');
-    } else {
+        type = getHtmlCreateType(jsTypeName);
-      func = getHtmlCreateFunction(jsTypeName);
+        if (type != null) return type;
-      if (func == null) {
-        // Start walking the prototype chain looking for a JS class.
-        var prototype = jsObject['__proto__'];
-        var keepWalking = true;
-        while (keepWalking && prototype.hasProperty('__proto__')) {
-          prototype = prototype['__proto__'];
-          if (prototype != null && prototype is Element &&
-              prototype.blink_jsObject != null) {
-            // We're a Dart class that's pointing to a JS class.
-            var blinkJso = prototype.blink_jsObject;
-            jsTypeName = blinkJso['constructor']['name'];
-            func = getHtmlCreateFunction(jsTypeName);
-            keepWalking = func == null;
-          }
-        }
       }
+      prototype = js.JsNative.getProperty(prototype, '__proto__');
     }
-
-    // Can we construct a Dart class?
-    if (func != null) {
-      dartClass_instance = func();
-
-      // Wrap our Dart instance in both directions.
-      dartClass_instance.blink_jsObject = jsObject;
-      js.setDartHtmlWrapperFor(jsObject, dartClass_instance);
-    }
-
-    // TODO(jacobr): cache that this is not a dart:html JS class.
-    return dartClass_instance;
   } catch (e, stacktrace) {
-    if (interop_checks) {
+    if (e is DebugAssertException) print("${e.message}\n ${stacktrace}");
-      if (e is DebugAssertException) window.console
+    else print("${stacktrace}");
-          .log("${e.message}\n ${stacktrace}");
-      else window.console.log("${stacktrace}");
-    }
   }
-
+  return js.JSObject.instanceRuntimeType;
-  return null;
-}
-
-/**
- * Create Dart class that maps to the JS Type, add the JsObject as an expando
- * on the Dart class and return the created Dart class.
- */
-wrap_jso_no_SerializedScriptvalue(jsObject) {
-  try {
-    if (jsObject is! js.JsObject || jsObject == null) {
-      // JS Interop converted the object to a Dart class e.g., Uint8ClampedList.
-      // or it's a simple type.
-      return jsObject;
-    }
-
-    // TODO(alanknight): With upgraded custom elements this causes a failure because
-    // we need a new wrapper after the type changes. We could possibly invalidate this
-    // if the constructor name didn't match?
-    var wrapper = js.getDartHtmlWrapperFor(jsObject);
-    if (wrapper != null) {
-      return wrapper;
-    }
-
-    if (jsObject is js.JsArray) {
-      wrapper = new js.JSArray.create(jsObject);
-      js.setDartHtmlWrapperFor(jsObject, wrapper);
-      return wrapper;
-    }
-    if (jsObject is js.JsFunction) {
-      wrapper = new js.JSFunction.create(jsObject);
-      js.setDartHtmlWrapperFor(jsObject, wrapper);
-      return wrapper;
-    }
-
-    var constructor = js.JsNative.getProperty(jsObject, 'constructor');
-    if (constructor == null) {
-      // Perfectly valid case for JavaScript objects where __proto__ has
-      // intentionally been set to null.
-      js.setDartHtmlWrapperFor(jsObject, new js.JSObject.create(jsObject));
-      return jsObject;
-    }
-    var jsTypeName = js.JsNative.getProperty(constructor, 'name');
-    if (jsTypeName is! String || jsTypeName.length == 0) {
-      // Not an html type.
-      wrapper = new js.JSObject.create(jsObject);
-      js.setDartHtmlWrapperFor(jsObject, wrapper);
-      return wrapper;
-    }
-
-    var func = getHtmlCreateFunction(jsTypeName);
-    if (func != null) {
-      var dartClass_instance = func();
-      dartClass_instance.blink_jsObject = jsObject;
-      js.setDartHtmlWrapperFor(jsObject, dartClass_instance);
-      return dartClass_instance;
-    }
-    wrapper = new js.JSObject.create(jsObject);
-    js.setDartHtmlWrapperFor(jsObject, wrapper);
-    return wrapper;
-  } catch (e, stacktrace) {
-    if (interop_checks) {
-      if (e is DebugAssertException) window.console
-          .log("${e.message}\n ${stacktrace}");
-      else window.console.log("${stacktrace}");
-    }
-  }
-
-  return null;
-}
-
-/**
- * Create Dart class that maps to the JS Type that is the JS type being
- * extended using JS interop createCallback (we need the base type of the
- * custom element) not the Dart created constructor.
- */
-wrap_jso_custom_element(jsObject) {
-  try {
-    if (jsObject is! js.JsObject) {
-      // JS Interop converted the object to a Dart class e.g., Uint8ClampedList.
-      return jsObject;
-    }
-
-    // Find out what object we're extending.
-    var objectName = jsObject.toString();
-    // Expect to see something like '[object HTMLElement]'.
-    if (!objectName.startsWith('[object ')) {
-      return jsObject;
-    }
-
-    var extendsClass = objectName.substring(8, objectName.length - 1);
-    var func = getHtmlCreateFunction(extendsClass);
-    if (interop_checks)
-      debug_or_assert("func != null name = ${extendsClass}", func != null);
-    var dartClass_instance = func();
-    dartClass_instance.blink_jsObject = jsObject;
-    return dartClass_instance;
-  } catch(e, stacktrace){
-    if (interop_checks) {
-      if (e is DebugAssertException)
-        window.console.log("${e.message}\n ${stacktrace}");
-      else
-        window.console.log("${stacktrace}");
-    }
-
-    // Problem?
-    return null;
-  }
-}
-
-getCustomElementEntry(element) {
-  var hasAttribute = false;
-
-  var jsObject;
-  var tag = "";
-  var runtimeType = element.runtimeType;
-  if (runtimeType == HtmlElement) {
-    tag = element.localName;
-  } else if (runtimeType == TemplateElement) {
-    // Data binding with a Dart class.
-    tag = element.attributes['is'];
-  } else if (runtimeType == js.JsObject) {
-    // It's a Polymer core element (written in JS).
-    // Make sure it's an element anything else we can ignore.
-    if (element.hasProperty('nodeType') && element['nodeType'] == 1) {
-      if (js.JsNative.callMethod(element, 'hasAttribute', ['is'])) {
-        hasAttribute = true;
-        // It's data binding use the is attribute.
-        tag = js.JsNative.callMethod(element, 'getAttribute', ['is']);
-      } else {
-        // It's a custom element we want the local name.
-        tag = element['localName'];
-      }
-    }
-  } else {
-    throw new UnsupportedError(
-        'Element is incorrect type. Got ${runtimeType}, expected HtmlElement/HtmlTemplate/JsObject.');
-  }
-
-  var entry = _knownCustomElements[tag];
-  if (entry != null) {
-    // If there's an 'is' attribute then check if the extends tag registered
-    // matches the tag if so then return the entry that's registered for this
-    // extendsTag or if there's no 'is' tag then return the entry found.
-    if ((hasAttribute && entry['extends'] == tag) || !hasAttribute) {
-      return entry;
-    }
-  }
-
-  return null;
-}
-
-// List of known tagName to DartClass for custom elements, used for upgrade.
-var _knownCustomElements = new Map<String, Map<Type, String>>();
-
-void addCustomElementType(String tagName, Type dartClass, [String extendTag]) {
-  _knownCustomElements[tagName] =
-      {'type': dartClass, 'extends': extendTag != null ? extendTag : "" };
-}
-
-Type getCustomElementType(object) {
-  var entry = getCustomElementEntry(object);
-  if (entry != null) {
-    return entry['type'];
-  }
-  return null;
 }

sdk/lib/indexed_db/dartium/indexed_db_dartium.dart

@@ -110,37 +110,83 @@ class _KeyRangeFactoryProvider {
 // FIXME: Can we make this private?
 @Deprecated("Internal Use Only")
 final indexed_dbBlinkMap = {
-  'IDBCursor': () => Cursor,
+  'IDBCursor': () => Cursor.instanceRuntimeType,
-  'IDBCursorWithValue': () => CursorWithValue,
+  'IDBCursorWithValue': () => CursorWithValue.instanceRuntimeType,
-  'IDBDatabase': () => Database,
+  'IDBDatabase': () => Database.instanceRuntimeType,
-  'IDBFactory': () => IdbFactory,
+  'IDBFactory': () => IdbFactory.instanceRuntimeType,
-  'IDBIndex': () => Index,
+  'IDBIndex': () => Index.instanceRuntimeType,
-  'IDBKeyRange': () => KeyRange,
+  'IDBKeyRange': () => KeyRange.instanceRuntimeType,
-  'IDBObjectStore': () => ObjectStore,
+  'IDBObjectStore': () => ObjectStore.instanceRuntimeType,
-  'IDBOpenDBRequest': () => OpenDBRequest,
+  'IDBOpenDBRequest': () => OpenDBRequest.instanceRuntimeType,
-  'IDBRequest': () => Request,
+  'IDBRequest': () => Request.instanceRuntimeType,
-  'IDBTransaction': () => Transaction,
+  'IDBTransaction': () => Transaction.instanceRuntimeType,
-  'IDBVersionChangeEvent': () => VersionChangeEvent,
+  'IDBVersionChangeEvent': () => VersionChangeEvent.instanceRuntimeType,
 
 };
 
-// FIXME: Can we make this private?
-@Deprecated("Internal Use Only")
-final indexed_dbBlinkFunctionMap = {
-  'IDBCursor': () => Cursor.internalCreateCursor,
-  'IDBCursorWithValue': () => CursorWithValue.internalCreateCursorWithValue,
-  'IDBDatabase': () => Database.internalCreateDatabase,
-  'IDBFactory': () => IdbFactory.internalCreateIdbFactory,
-  'IDBIndex': () => Index.internalCreateIndex,
-  'IDBKeyRange': () => KeyRange.internalCreateKeyRange,
-  'IDBObjectStore': () => ObjectStore.internalCreateObjectStore,
-  'IDBOpenDBRequest': () => OpenDBRequest.internalCreateOpenDBRequest,
-  'IDBRequest': () => Request.internalCreateRequest,
-  'IDBTransaction': () => Transaction.internalCreateTransaction,
-  'IDBVersionChangeEvent': () => VersionChangeEvent.internalCreateVersionChangeEvent,
 
-};
+//
-// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
+// Per http://www.w3.org/TR/IndexedDB/#key-construct
+//
+// "A value is said to be a valid key if it is one of the following types: Array
+// JavaScript objects [ECMA-262], DOMString [WEBIDL], Date [ECMA-262] or float
+// [WEBIDL]. However Arrays are only valid keys if every item in the array is
+// defined and is a valid key (i.e. sparse arrays can not be valid keys) and if
+// the Array doesn't directly or indirectly contain itself. Any non-numeric
+// properties are ignored, and thus does not affect whether the Array is a valid
+// key. Additionally, if the value is of type float, it is only a valid key if
+// it is not NaN, and if the value is of type Date it is only a valid key if its
+// [[PrimitiveValue]] internal property, as defined by [ECMA-262], is not NaN."
+
+// What is required is to ensure that an Lists in the key are actually
+// JavaScript arrays, and any Dates are JavaScript Dates.
+
+
+/**
+ * Converts a native IDBKey into a Dart object.
+ *
+ * May return the original input.  May mutate the original input (but will be
+ * idempotent if mutation occurs).  It is assumed that this conversion happens
+ * on native IDBKeys on all paths that return IDBKeys from native DOM calls.
+ *
+ * If necessary, JavaScript Dates are converted into Dart Dates.
+ */
+_convertNativeToDart_IDBKey(nativeKey) {
+  containsDate(object) {
+    if (object is DateTime) return true;
+    if (object is List) {
+      for (int i = 0; i < object.length; i++) {
+        if (containsDate(object[i])) return true;
+      }
+    }
+    return false;  // number, string.
+  }
+  if (nativeKey is DateTime) {
+    throw new UnimplementedError('Key containing DateTime');
+  }
+  // TODO: Cache conversion somewhere?
+  return nativeKey;
+}
+
+/**
+ * Converts a Dart object into a valid IDBKey.
+ *
+ * May return the original input.  Does not mutate input.
+ *
+ * If necessary, [dartKey] may be copied to ensure all lists are converted into
+ * JavaScript Arrays and Dart Dates into JavaScript Dates.
+ */
+_convertDartToNative_IDBKey(dartKey) {
+  // TODO: Implement.
+  return dartKey;
+}
+
+
+
+/// May modify original.  If so, action is idempotent.
+_convertNativeToDart_IDBAny(object) {
+  return convertNativeToDart_AcceptStructuredClone(object, mustCopy: false);
+}// Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
@@ -169,62 +215,54 @@ class Cursor extends DartHtmlDomObject {
     // To suppress missing implicit constructor warnings.
   factory Cursor._() { throw new UnsupportedError("Not supported"); }
 
-  @Deprecated("Internal Use Only")
-  static Cursor internalCreateCursor() {
-    return new Cursor._internalWrap();
-  }
 
-  factory Cursor._internalWrap() {
+  @Deprecated("Internal Use Only")
-    return new Cursor.internal_();
+  external static Type get instanceRuntimeType;
-  }
 
   @Deprecated("Internal Use Only")
   Cursor.internal_() { }
 
-  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);
-  int get hashCode => unwrap_jso(this).hashCode;
-
   @DomName('IDBCursor.direction')
   @DocsEditable()
-  String get direction => _blink.BlinkIDBCursor.instance.direction_Getter_(unwrap_jso(this));
+  String get direction => _blink.BlinkIDBCursor.instance.direction_Getter_(this);
   
   @DomName('IDBCursor.key')
   @DocsEditable()
-  Object get key => wrap_jso(_blink.BlinkIDBCursor.instance.key_Getter_(unwrap_jso(this)));
+  Object get key => (_blink.BlinkIDBCursor.instance.key_Getter_(this));
   
   @DomName('IDBCursor.primaryKey')
   @DocsEditable()
-  Object get primaryKey => wrap_jso(_blink.BlinkIDBCursor.instance.primaryKey_Getter_(unwrap_jso(this)));
+  Object get primaryKey => (_blink.BlinkIDBCursor.instance.primaryKey_Getter_(this));
   
   @DomName('IDBCursor.source')
   @DocsEditable()
-  Object get source => wrap_jso(_blink.BlinkIDBCursor.instance.source_Getter_(unwrap_jso(this)));
+  Object get source => (_blink.BlinkIDBCursor.instance.source_Getter_(this));
   
   @DomName('IDBCursor.advance')
   @DocsEditable()
-  void advance(int count) => _blink.BlinkIDBCursor.instance.advance_Callback_1_(unwrap_jso(this), count);
+  void advance(int count) => _blink.BlinkIDBCursor.instance.advance_Callback_1_(this, count);
   
   @DomName('IDBCursor.continuePrimaryKey')
   @DocsEditable()
   @Experimental() // untriaged
-  void continuePrimaryKey(Object key, Object primaryKey) => _blink.BlinkIDBCursor.instance.continuePrimaryKey_Callback_2_(unwrap_jso(this), key, primaryKey);
+  void continuePrimaryKey(Object key, Object primaryKey) => _blink.BlinkIDBCursor.instance.continuePrimaryKey_Callback_2_(this, key, primaryKey);
   
   @DomName('IDBCursor.delete')
   @DocsEditable()
-  Request _delete() => wrap_jso(_blink.BlinkIDBCursor.instance.delete_Callback_0_(unwrap_jso(this)));
+  Request _delete() => _blink.BlinkIDBCursor.instance.delete_Callback_0_(this);
   
   void next([Object key]) {
     if (key != null) {
-      _blink.BlinkIDBCursor.instance.continue_Callback_1_(unwrap_jso(this), key);
+      _blink.BlinkIDBCursor.instance.continue_Callback_1_(this, key);
       return;
     }
-    _blink.BlinkIDBCursor.instance.continue_Callback_0_(unwrap_jso(this));
+    _blink.BlinkIDBCursor.instance.continue_Callback_0_(this);
     return;
   }
 
   @DomName('IDBCursor.update')
   @DocsEditable()
-  Request _update(Object value) => wrap_jso(_blink.BlinkIDBCursor.instance.update_Callback_1_(unwrap_jso(this), convertDartToNative_SerializedScriptValue(value)));
+  Request _update(Object value) => _blink.BlinkIDBCursor.instance.update_Callback_1_(this, convertDartToNative_SerializedScriptValue(value));
   
 }
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
@@ -243,11 +281,7 @@ class CursorWithValue extends Cursor {
 
 
   @Deprecated("Internal Use Only")
-  static CursorWithValue internalCreateCursorWithValue() {
+  external static Type get instanceRuntimeType;
-    return new CursorWithValue._internalWrap();
-  }
-
-  external factory CursorWithValue._internalWrap();
 
   @Deprecated("Internal Use Only")
   CursorWithValue.internal_() : super.internal_();
@@ -255,7 +289,7 @@ class CursorWithValue extends Cursor {
 
   @DomName('IDBCursorWithValue.value')
   @DocsEditable()
-  Object get value => wrap_jso(_blink.BlinkIDBCursorWithValue.instance.value_Getter_(unwrap_jso(this)));
+  Object get value => _convertNativeToDart_IDBAny(_blink.BlinkIDBCursorWithValue.instance.value_Getter_(this));
   
 }
 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
@@ -298,14 +332,14 @@ class Database extends EventTarget {
     if (storeName_OR_storeNames == null) {
       throw new ArgumentError("stores may not be null in transaction");
     } else if (storeName_OR_storeNames is String || storeName_OR_storeNames is DomStringList) {
-      names = unwrap_jso(storeName_OR_storeNames);
+      names = storeName_OR_storeNames;
     } else if (storeName_OR_storeNames is List<String>) {
       names = convertDartToNative_List(storeName_OR_storeNames);
     } else {
       throw new ArgumentError("Invalid store(s) $store_Name_OR_storeNames");
     }
 
-    return wrap_jso(_blink.BlinkIDBDatabase.instance.transaction_Callback_2_(unwrap_jso(this), names, mode));
+    return _blink.BlinkIDBDatabase.instance.transaction_Callback_2_(this, names, mode);
   }
 
   Transaction transactionList(List<String> storeNames, String mode) => transaction(storeNames, mode);
@@ -359,11 +393,7 @@ class Database extends EventTarget {
 
 
   @Deprecated("Internal Use Only")
-  static Database internalCreateDatabase() {
+  external static Type get instanceRuntimeType;
-    return new Database._internalWrap();
-  }
-
-  external factory Database._internalWrap();
 
   @Deprecated("Internal Use Only")
   Database.internal_() : super.internal_();
@@ -371,30 +401,30 @@ class Database extends EventTarget {
 
   @DomName('IDBDatabase.name')
   @DocsEditable()
-  String get name => _blink.BlinkIDBDatabase.instance.name_Getter_(unwrap_jso(this));
+  String get name => _blink.BlinkIDBDatabase.instance.name_Getter_(this);
   
   @DomName('IDBDatabase.objectStoreNames')
   @DocsEditable()
-  List<String> get objectStoreNames => wrap_jso(_blink.BlinkIDBDatabase.instance.objectStoreNames_Getter_(unwrap_jso(this)));
+  List<String> get objectStoreNames => _blink.BlinkIDBDatabase.instance.objectStoreNames_Getter_(this);
   
   @DomName('IDBDatabase.version')
   @DocsEditable()
-  Object get version => wrap_jso(_blink.BlinkIDBDatabase.instance.version_Getter_(unwrap_jso(this)));
+  Object get version => (_blink.BlinkIDBDatabase.instance.version_Getter_(this));
   
   @DomName('IDBDatabase.close')
   @DocsEditable()
-  void close() => _blink.BlinkIDBDatabase.instance.close_Callback_0_(unwrap_jso(this));
+  void close() => _blink.BlinkIDBDatabase.instance.close_Callback_0_(this);
   
   ObjectStore _createObjectStore(String name, [Map options]) {
     if (options != null) {
-      return wrap_jso(_blink.BlinkIDBDatabase.instance.createObjectStore_Callback_2_(unwrap_jso(this), name, convertDartToNative_Dictionary(options)));
+      return _blink.BlinkIDBDatabase.instance.createObjectStore_Callback_2_(this, name, convertDartToNative_Dictionary(options));
     }
-    return wrap_jso(_blink.BlinkIDBDatabase.instance.createObjectStore_Callback_1_(unwrap_jso(this), name));
+    return _blink.BlinkIDBDatabase.instance.createObjectStore_Callback_1_(this, name);
   }
 
   @DomName('IDBDatabase.deleteObjectStore')
   @DocsEditable()
-  void deleteObjectStore(String name) => _blink.BlinkIDBDatabase.instance.deleteObjectStore_Callback_1_(unwrap_jso(this), name);
+  void deleteObjectStore(String name) => _blink.BlinkIDBDatabase.instance.deleteObjectStore_Callback_1_(this, name);
   
   /// Stream of `abort` events handled by this [Database].
   @DomName('IDBDatabase.onabort')
@@ -508,34 +538,26 @@ class IdbFactory extends DartHtmlDomObject {
   // To suppress missing implicit constructor warnings.
   factory IdbFactory._() { throw new UnsupportedError("Not supported"); }
 
-  @Deprecated("Internal Use Only")
-  static IdbFactory internalCreateIdbFactory() {
-    return new IdbFactory._internalWrap();
-  }
 
-  factory IdbFactory._internalWrap() {
+  @Deprecated("Internal Use Only")
-    return new IdbFactory.internal_();
+  external static Type get instanceRuntimeType;
-  }
 
   @Deprecated("Internal Use Only")
   IdbFactory.internal_() { }
 
-  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);
-  int get hashCode => unwrap_jso(this).hashCode;
-
   @DomName('IDBFactory.cmp')
   @DocsEditable()
-  int cmp(Object first, Object second) => _blink.BlinkIDBFactory.instance.cmp_Callback_2_(unwrap_jso(this), first, second);
+  int cmp(Object first, Object second) => _blink.BlinkIDBFactory.instance.cmp_Callback_2_(this, first, second);
   
   @DomName('IDBFactory.deleteDatabase')
   @DocsEditable()
-  OpenDBRequest _deleteDatabase(String name) => wrap_jso(_blink.BlinkIDBFactory.instance.deleteDatabase_Callback_1_(unwrap_jso(this), name));
+  OpenDBRequest _deleteDatabase(String name) => _blink.BlinkIDBFactory.instance.deleteDatabase_Callback_1_(this, name);
   
   OpenDBRequest _open(String name, [int version]) {
     if (version != null) {
-      return wrap_jso(_blink.BlinkIDBFactory.instance.open_Callback_2_(unwrap_jso(this), name, version));
+      return _blink.BlinkIDBFactory.instance.open_Callback_2_(this, name, version);
     }
-    return wrap_jso(_blink.BlinkIDBFactory.instance.open_Callback_1_(unwrap_jso(this), name));
+    return _blink.BlinkIDBFactory.instance.open_Callback_1_(this, name);
   }
 
   @DomName('IDBFactory.webkitGetDatabaseNames')
@@ -543,7 +565,7 @@ class IdbFactory extends DartHtmlDomObject {
   @SupportedBrowser(SupportedBrowser.CHROME)
   @SupportedBrowser(SupportedBrowser.SAFARI)
   @Experimental()
-  Request _webkitGetDatabaseNames() => wrap_jso(_blink.BlinkIDBFactory.instance.webkitGetDatabaseNames_Callback_0_(unwrap_jso(this)));
+  Request _webkitGetDatabaseNames() => _blink.BlinkIDBFactory.instance.webkitGetDatabaseNames_Callback_0_(this);
   
 }
 
@@ -661,79 +683,71 @@ class Index extends DartHtmlDomObject {
     // To suppress missing implicit constructor warnings.
   factory Index._() { throw new UnsupportedError("Not supported"); }
 
-  @Deprecated("Internal Use Only")
-  static Index internalCreateIndex() {
-    return new Index._internalWrap();
-  }
 
-  factory Index._internalWrap() {
+  @Deprecated("Internal Use Only")
-    return new Index.internal_();
+  external static Type get instanceRuntimeType;
-  }
 
   @Deprecated("Internal Use Only")
   Index.internal_() { }
 
-  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);
-  int get hashCode => unwrap_jso(this).hashCode;
-
   @DomName('IDBIndex.keyPath')
   @DocsEditable()
-  Object get keyPath => wrap_jso(_blink.BlinkIDBIndex.instance.keyPath_Getter_(unwrap_jso(this)));
+  Object get keyPath => (_blink.BlinkIDBIndex.instance.keyPath_Getter_(this));
   
   @DomName('IDBIndex.multiEntry')
   @DocsEditable()
-  bool get multiEntry => _blink.BlinkIDBIndex.instance.multiEntry_Getter_(unwrap_jso(this));
+  bool get multiEntry => _blink.BlinkIDBIndex.instance.multiEntry_Getter_(this);
   
   @DomName('IDBIndex.name')
   @DocsEditable()
-  String get name => _blink.BlinkIDBIndex.instance.name_Getter_(unwrap_jso(this));
+  String get name => _blink.BlinkIDBIndex.instance.name_Getter_(this);
   
   @DomName('IDBIndex.objectStore')
   @DocsEditable()
-  ObjectStore get objectStore => wrap_jso(_blink.BlinkIDBIndex.instance.objectStore_Getter_(unwrap_jso(this)));
+  ObjectStore get objectStore => _blink.BlinkIDBIndex.instance.objectStore_Getter_(this);
   
   @DomName('IDBIndex.unique')
   @DocsEditable()
-  bool get unique => _blink.BlinkIDBIndex.instance.unique_Getter_(unwrap_jso(this));
+  bool get unique => _blink.BlinkIDBIndex.instance.unique_Getter_(this);
   
   @DomName('IDBIndex.count')
   @DocsEditable()
-  Request _count(Object key) => wrap_jso(_blink.BlinkIDBIndex.instance.count_Callback_1_(unwrap_jso(this), key));
+  Request _count(Object key) => _blink.BlinkIDBIndex.instance.count_Callback_1_(this, key);
   
   @DomName('IDBIndex.get')
   @DocsEditable()
-  Request _get(Object key) => wrap_jso(_blink.BlinkIDBIndex.instance.get_Callback_1_(unwrap_jso(this), key));
+  Request _get(Object key) => _blink.BlinkIDBIndex.instance.get_Callback_1_(this, key);
   
   Request getAll(Object range, [int maxCount]) {
     if (maxCount != null) {
-      return wrap_jso(_blink.BlinkIDBIndex.instance.getAll_Callback_2_(unwrap_jso(this), range, maxCount));
+      return _blink.BlinkIDBIndex.instance.getAll_Callback_2_(this, range, maxCount);
     }
-    return wrap_jso(_blink.BlinkIDBIndex.instance.getAll_Callback_1_(unwrap_jso(this), range));
+    return _blink.BlinkIDBIndex.instance.getAll_Callback_1_(this, range);
   }
 
   Request getAllKeys(Object range, [int maxCount]) {
     if (maxCount != null) {
-      return wrap_jso(_blink.BlinkIDBIndex.instance.getAllKeys_Callback_2_(unwrap_jso(this), range, maxCount));
+      return _blink.BlinkIDBIndex.instance.getAllKeys_Callback_2_(this, range, maxCount);
     }
-    return wrap_jso(_blink.BlinkIDBIndex.instance.getAllKeys_Callback_1_(unwrap_jso(this), range));
+    return _blink.BlinkIDBIndex.instance.getAllKeys_Callback_1_(this, range);
   }
 
   @DomName('IDBIndex.getKey')
   @DocsEditable()
-  Request _getKey(Object key) => wrap_jso(_blink.BlinkIDBIndex.instance.getKey_Callback_1_(unwrap_jso(this), key));
+  Request _getKey(Object key) => _blink.BlinkIDBIndex.instance.getKey_Callback_1_(this, key);
   
   Request _openCursor(Object range, [String direction]) {
     if (direction != null) {
-      return wrap_jso(_blink.BlinkIDBIndex.instance.openCursor_Callback_2_(unwrap_jso(this), range, direction));
+      return _blink.BlinkIDBIndex.instance.openCursor_Callback_2_(this, range, direction);
     }
-    return wrap_jso(_blink.BlinkIDBIndex.instance.openCursor_Callback_1_(unwrap_jso(this), range));
+    return _blink.BlinkIDBIndex.instance.openCursor_Callback_1_(this, range);
   }
 
   Request _openKeyCursor(Object range, [String direction]) {
     if (direction != null) {
-      return wrap_jso(_blink.BlinkIDBIndex.instance.openKeyCursor_Callback_2_(unwrap_jso(this), range, direction));
+      return _blink.BlinkIDBIndex.instance.openKeyCursor_Callback_2_(this, range, direction);
     }
-    return wrap_jso(_blink.BlinkIDBIndex.instance.openKeyCursor_Callback_1_(unwrap_jso(this), range));
+    return _blink.BlinkIDBIndex.instance.openKeyCursor_Callback_1_(this, range);
   }
 
 }
@@ -766,64 +780,56 @@ class KeyRange extends DartHtmlDomObject {
   // To suppress missing implicit constructor warnings.
   factory KeyRange._() { throw new UnsupportedError("Not supported"); }
 
-  @Deprecated("Internal Use Only")
-  static KeyRange internalCreateKeyRange() {
-    return new KeyRange._internalWrap();
-  }
 
-  factory KeyRange._internalWrap() {
+  @Deprecated("Internal Use Only")
-    return new KeyRange.internal_();
+  external static Type get instanceRuntimeType;
-  }
 
   @Deprecated("Internal Use Only")
   KeyRange.internal_() { }
 
-  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);
-  int get hashCode => unwrap_jso(this).hashCode;
-
   @DomName('IDBKeyRange.lower')
   @DocsEditable()
-  Object get lower => wrap_jso(_blink.BlinkIDBKeyRange.instance.lower_Getter_(unwrap_jso(this)));
+  Object get lower => (_blink.BlinkIDBKeyRange.instance.lower_Getter_(this));
   
   @DomName('IDBKeyRange.lowerOpen')
   @DocsEditable()
-  bool get lowerOpen => _blink.BlinkIDBKeyRange.instance.lowerOpen_Getter_(unwrap_jso(this));
+  bool get lowerOpen => _blink.BlinkIDBKeyRange.instance.lowerOpen_Getter_(this);
   
   @DomName('IDBKeyRange.upper')
   @DocsEditable()
-  Object get upper => wrap_jso(_blink.BlinkIDBKeyRange.instance.upper_Getter_(unwrap_jso(this)));
+  Object get upper => (_blink.BlinkIDBKeyRange.instance.upper_Getter_(this));
   
   @DomName('IDBKeyRange.upperOpen')
   @DocsEditable()
-  bool get upperOpen => _blink.BlinkIDBKeyRange.instance.upperOpen_Getter_(unwrap_jso(this));
+  bool get upperOpen => _blink.BlinkIDBKeyRange.instance.upperOpen_Getter_(this);
   
   static KeyRange bound_(Object lower, Object upper, [bool lowerOpen, bool upperOpen]) {
     if (upperOpen != null) {
-      return wrap_jso(_blink.BlinkIDBKeyRange.instance.bound_Callback_4_(lower, upper, lowerOpen, upperOpen));
+      return _blink.BlinkIDBKeyRange.instance.bound_Callback_4_(lower, upper, lowerOpen, upperOpen);
     }
     if (lowerOpen != null) {
-      return wrap_jso(_blink.BlinkIDBKeyRange.instance.bound_Callback_3_(lower, upper, lowerOpen));
+      return _blink.BlinkIDBKeyRange.instance.bound_Callback_3_(lower, upper, lowerOpen);
     }
-    return wrap_jso(_blink.BlinkIDBKeyRange.instance.bound_Callback_2_(lower, upper));
+    return _blink.BlinkIDBKeyRange.instance.bound_Callback_2_(lower, upper);
   }
 
   static KeyRange lowerBound_(Object bound, [bool open]) {
     if (open != null) {
-      return wrap_jso(_blink.BlinkIDBKeyRange.instance.lowerBound_Callback_2_(bound, open));
+      return _blink.BlinkIDBKeyRange.instance.lowerBound_Callback_2_(bound, open);
     }
-    return wrap_jso(_blink.BlinkIDBKeyRange.instance.lowerBound_Callback_1_(bound));
+    return _blink.BlinkIDBKeyRange.instance.lowerBound_Callback_1_(bound);
   }
 
   @DomName('IDBKeyRange.only_')
   @DocsEditable()
   @Experimental() // non-standard
-  static KeyRange only_(Object value) => wrap_jso(_blink.BlinkIDBKeyRange.instance.only_Callback_1_(value));
+  static KeyRange only_(Object value) => _blink.BlinkIDBKeyRange.instance.only_Callback_1_(value);
   
   static KeyRange upperBound_(Object bound, [bool open]) {
     if (open != null) {
-      return wrap_jso(_blink.BlinkIDBKeyRange.instance.upperBound_Callback_2_(bound, open));
+      return _blink.BlinkIDBKeyRange.instance.upperBound_Callback_2_(bound, open);
     }
-    return wrap_jso(_blink.BlinkIDBKeyRange.instance.upperBound_Callback_1_(bound));
+    return _blink.BlinkIDBKeyRange.instance.upperBound_Callback_1_(bound);
   }
 
 }
@@ -965,112 +971,104 @@ class ObjectStore extends DartHtmlDomObject {
   // To suppress missing implicit constructor warnings.
   factory ObjectStore._() { throw new UnsupportedError("Not supported"); }
 
-  @Deprecated("Internal Use Only")
-  static ObjectStore internalCreateObjectStore() {
-    return new ObjectStore._internalWrap();
-  }
 
-  factory ObjectStore._internalWrap() {
+  @Deprecated("Internal Use Only")
-    return new ObjectStore.internal_();
+  external static Type get instanceRuntimeType;
-  }
 
   @Deprecated("Internal Use Only")
   ObjectStore.internal_() { }
 
-  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);
-  int get hashCode => unwrap_jso(this).hashCode;
-
   @DomName('IDBObjectStore.autoIncrement')
   @DocsEditable()
-  bool get autoIncrement => _blink.BlinkIDBObjectStore.instance.autoIncrement_Getter_(unwrap_jso(this));
+  bool get autoIncrement => _blink.BlinkIDBObjectStore.instance.autoIncrement_Getter_(this);
   
   @DomName('IDBObjectStore.indexNames')
   @DocsEditable()
-  List<String> get indexNames => wrap_jso(_blink.BlinkIDBObjectStore.instance.indexNames_Getter_(unwrap_jso(this)));
+  List<String> get indexNames => _blink.BlinkIDBObjectStore.instance.indexNames_Getter_(this);
   
   @DomName('IDBObjectStore.keyPath')
   @DocsEditable()
-  Object get keyPath => wrap_jso(_blink.BlinkIDBObjectStore.instance.keyPath_Getter_(unwrap_jso(this)));
+  Object get keyPath => (_blink.BlinkIDBObjectStore.instance.keyPath_Getter_(this));
   
   @DomName('IDBObjectStore.name')
   @DocsEditable()
-  String get name => _blink.BlinkIDBObjectStore.instance.name_Getter_(unwrap_jso(this));
+  String get name => _blink.BlinkIDBObjectStore.instance.name_Getter_(this);
   
   @DomName('IDBObjectStore.transaction')
   @DocsEditable()
-  Transaction get transaction => wrap_jso(_blink.BlinkIDBObjectStore.instance.transaction_Getter_(unwrap_jso(this)));
+  Transaction get transaction => _blink.BlinkIDBObjectStore.instance.transaction_Getter_(this);
   
   Request _add(Object value, [Object key]) {
     if (key != null) {
-      return wrap_jso(_blink.BlinkIDBObjectStore.instance.add_Callback_2_(unwrap_jso(this), convertDartToNative_SerializedScriptValue(value), convertDartToNative_SerializedScriptValue(key)));
+      return _blink.BlinkIDBObjectStore.instance.add_Callback_2_(this, convertDartToNative_SerializedScriptValue(value), convertDartToNative_SerializedScriptValue(key));
     }
-    return wrap_jso(_blink.BlinkIDBObjectStore.instance.add_Callback_1_(unwrap_jso(this), convertDartToNative_SerializedScriptValue(value)));
+    return _blink.BlinkIDBObjectStore.instance.add_Callback_1_(this, convertDartToNative_SerializedScriptValue(value));
   }
 
   @DomName('IDBObjectStore.clear')
   @DocsEditable()
-  Request _clear() => wrap_jso(_blink.BlinkIDBObjectStore.instance.clear_Callback_0_(unwrap_jso(this)));
+  Request _clear() => _blink.BlinkIDBObjectStore.instance.clear_Callback_0_(this);
   
   @DomName('IDBObjectStore.count')
   @DocsEditable()
-  Request _count(Object key) => wrap_jso(_blink.BlinkIDBObjectStore.instance.count_Callback_1_(unwrap_jso(this), key));
+  Request _count(Object key) => _blink.BlinkIDBObjectStore.instance.count_Callback_1_(this, key);
   
   Index _createIndex(String name, Object keyPath, [Map options]) {
     if (options != null) {
-      return wrap_jso(_blink.BlinkIDBObjectStore.instance.createIndex_Callback_3_(unwrap_jso(this), name, keyPath, convertDartToNative_Dictionary(options)));
+      return _blink.BlinkIDBObjectStore.instance.createIndex_Callback_3_(this, name, keyPath, convertDartToNative_Dictionary(options));
     }
-    return wrap_jso(_blink.BlinkIDBObjectStore.instance.createIndex_Callback_2_(unwrap_jso(this), name, keyPath));
+    return _blink.BlinkIDBObjectStore.instance.createIndex_Callback_2_(this, name, keyPath);
   }
 
   @DomName('IDBObjectStore.delete')
   @DocsEditable()
-  Request _delete(Object key) => wrap_jso(_blink.BlinkIDBObjectStore.instance.delete_Callback_1_(unwrap_jso(this), key));
+  Request _delete(Object key) => _blink.BlinkIDBObjectStore.instance.delete_Callback_1_(this, key);
   
   @DomName('IDBObjectStore.deleteIndex')
   @DocsEditable()
-  void deleteIndex(String name) => _blink.BlinkIDBObjectStore.instance.deleteIndex_Callback_1_(unwrap_jso(this), name);
+  void deleteIndex(String name) => _blink.BlinkIDBObjectStore.instance.deleteIndex_Callback_1_(this, name);
   
   @DomName('IDBObjectStore.get')
   @DocsEditable()
-  Request _get(Object key) => wrap_jso(_blink.BlinkIDBObjectStore.instance.get_Callback_1_(unwrap_jso(this), key));
+  Request _get(Object key) => _blink.BlinkIDBObjectStore.instance.get_Callback_1_(this, key);
   
   Request getAll(Object range, [int maxCount]) {
     if (maxCount != null) {
-      return wrap_jso(_blink.BlinkIDBObjectStore.instance.getAll_Callback_2_(unwrap_jso(this), range, maxCount));
+      return _blink.BlinkIDBObjectStore.instance.getAll_Callback_2_(this, range, maxCount);
     }
-    return wrap_jso(_blink.BlinkIDBObjectStore.instance.getAll_Callback_1_(unwrap_jso(this), range));
+    return _blink.BlinkIDBObjectStore.instance.getAll_Callback_1_(this, range);
   }
 
   Request getAllKeys(Object range, [int maxCount]) {
     if (maxCount != null) {
-      return wrap_jso(_blink.BlinkIDBObjectStore.instance.getAllKeys_Callback_2_(unwrap_jso(this), range, maxCount));
+      return _blink.BlinkIDBObjectStore.instance.getAllKeys_Callback_2_(this, range, maxCount);
     }
-    return wrap_jso(_blink.BlinkIDBObjectStore.instance.getAllKeys_Callback_1_(unwrap_jso(this), range));
+    return _blink.BlinkIDBObjectStore.instance.getAllKeys_Callback_1_(this, range);
   }
 
   @DomName('IDBObjectStore.index')
   @DocsEditable()
-  Index index(String name) => wrap_jso(_blink.BlinkIDBObjectStore.instance.index_Callback_1_(unwrap_jso(this), name));
+  Index index(String name) => _blink.BlinkIDBObjectStore.instance.index_Callback_1_(this, name);
   
   Request _openCursor(Object range, [String direction]) {
     if (direction != null) {
-      return wrap_jso(_blink.BlinkIDBObjectStore.instance.openCursor_Callback_2_(unwrap_jso(this), range, direction));
+      return _blink.BlinkIDBObjectStore.instance.openCursor_Callback_2_(this, range, direction);
     }
-    return wrap_jso(_blink.BlinkIDBObjectStore.instance.openCursor_Callback_1_(unwrap_jso(this), range));
+    return _blink.BlinkIDBObjectStore.instance.openCursor_Callback_1_(this, range);
   }
 
   Request openKeyCursor(Object range, [String direction]) {
     if (direction != null) {
-      return wrap_jso(_blink.BlinkIDBObjectStore.instance.openKeyCursor_Callback_2_(unwrap_jso(this), range, direction));
+      return _blink.BlinkIDBObjectStore.instance.openKeyCursor_Callback_2_(this, range, direction);
     }
-    return wrap_jso(_blink.BlinkIDBObjectStore.instance.openKeyCursor_Callback_1_(unwrap_jso(this), range));
+    return _blink.BlinkIDBObjectStore.instance.openKeyCursor_Callback_1_(this, range);
   }
 
   Request _put(Object value, [Object key]) {
     if (key != null) {
-      return wrap_jso(_blink.BlinkIDBObjectStore.instance.put_Callback_2_(unwrap_jso(this), convertDartToNative_SerializedScriptValue(value), convertDartToNative_SerializedScriptValue(key)));
+      return _blink.BlinkIDBObjectStore.instance.put_Callback_2_(this, convertDartToNative_SerializedScriptValue(value), convertDartToNative_SerializedScriptValue(key));
     }
-    return wrap_jso(_blink.BlinkIDBObjectStore.instance.put_Callback_1_(unwrap_jso(this), convertDartToNative_SerializedScriptValue(value)));
+    return _blink.BlinkIDBObjectStore.instance.put_Callback_1_(this, convertDartToNative_SerializedScriptValue(value));
   }
 
 
@@ -1137,11 +1135,7 @@ class OpenDBRequest extends Request {
 
 
   @Deprecated("Internal Use Only")
-  static OpenDBRequest internalCreateOpenDBRequest() {
+  external static Type get instanceRuntimeType;
-    return new OpenDBRequest._internalWrap();
-  }
-
-  external factory OpenDBRequest._internalWrap();
 
   @Deprecated("Internal Use Only")
   OpenDBRequest.internal_() : super.internal_();
@@ -1194,11 +1188,7 @@ class Request extends EventTarget {
 
 
   @Deprecated("Internal Use Only")
-  static Request internalCreateRequest() {
+  external static Type get instanceRuntimeType;
-    return new Request._internalWrap();
-  }
-
-  external factory Request._internalWrap();
 
   @Deprecated("Internal Use Only")
   Request.internal_() : super.internal_();
@@ -1206,23 +1196,23 @@ class Request extends EventTarget {
 
   @DomName('IDBRequest.error')
   @DocsEditable()
-  DomError get error => wrap_jso(_blink.BlinkIDBRequest.instance.error_Getter_(unwrap_jso(this)));
+  DomError get error => _blink.BlinkIDBRequest.instance.error_Getter_(this);
   
   @DomName('IDBRequest.readyState')
   @DocsEditable()
-  String get readyState => _blink.BlinkIDBRequest.instance.readyState_Getter_(unwrap_jso(this));
+  String get readyState => _blink.BlinkIDBRequest.instance.readyState_Getter_(this);
   
   @DomName('IDBRequest.result')
   @DocsEditable()
-  Object get result => wrap_jso(_blink.BlinkIDBRequest.instance.result_Getter_(unwrap_jso(this)));
+  Object get result => _convertNativeToDart_IDBAny(_blink.BlinkIDBRequest.instance.result_Getter_(this));
   
   @DomName('IDBRequest.source')
   @DocsEditable()
-  Object get source => wrap_jso(_blink.BlinkIDBRequest.instance.source_Getter_(unwrap_jso(this)));
+  Object get source => (_blink.BlinkIDBRequest.instance.source_Getter_(this));
   
   @DomName('IDBRequest.transaction')
   @DocsEditable()
-  Transaction get transaction => wrap_jso(_blink.BlinkIDBRequest.instance.transaction_Getter_(unwrap_jso(this)));
+  Transaction get transaction => _blink.BlinkIDBRequest.instance.transaction_Getter_(this);
   
   /// Stream of `error` events handled by this [Request].
   @DomName('IDBRequest.onerror')
@@ -1307,11 +1297,7 @@ class Transaction extends EventTarget {
 
 
   @Deprecated("Internal Use Only")
-  static Transaction internalCreateTransaction() {
+  external static Type get instanceRuntimeType;
-    return new Transaction._internalWrap();
-  }
-
-  external factory Transaction._internalWrap();
 
   @Deprecated("Internal Use Only")
   Transaction.internal_() : super.internal_();
@@ -1319,28 +1305,28 @@ class Transaction extends EventTarget {
 
   @DomName('IDBTransaction.db')
   @DocsEditable()
-  Database get db => wrap_jso(_blink.BlinkIDBTransaction.instance.db_Getter_(unwrap_jso(this)));
+  Database get db => _blink.BlinkIDBTransaction.instance.db_Getter_(this);
   
   @DomName('IDBTransaction.error')
   @DocsEditable()
-  DomError get error => wrap_jso(_blink.BlinkIDBTransaction.instance.error_Getter_(unwrap_jso(this)));
+  DomError get error => _blink.BlinkIDBTransaction.instance.error_Getter_(this);
   
   @DomName('IDBTransaction.mode')
   @DocsEditable()
-  String get mode => _blink.BlinkIDBTransaction.instance.mode_Getter_(unwrap_jso(this));
+  String get mode => _blink.BlinkIDBTransaction.instance.mode_Getter_(this);
   
   @DomName('IDBTransaction.objectStoreNames')
   @DocsEditable()
   @Experimental() // untriaged
-  List<String> get objectStoreNames => wrap_jso(_blink.BlinkIDBTransaction.instance.objectStoreNames_Getter_(unwrap_jso(this)));
+  List<String> get objectStoreNames => _blink.BlinkIDBTransaction.instance.objectStoreNames_Getter_(this);
   
   @DomName('IDBTransaction.abort')
   @DocsEditable()
-  void abort() => _blink.BlinkIDBTransaction.instance.abort_Callback_0_(unwrap_jso(this));
+  void abort() => _blink.BlinkIDBTransaction.instance.abort_Callback_0_(this);
   
   @DomName('IDBTransaction.objectStore')
   @DocsEditable()
-  ObjectStore objectStore(String name) => wrap_jso(_blink.BlinkIDBTransaction.instance.objectStore_Callback_1_(unwrap_jso(this), name));
+  ObjectStore objectStore(String name) => _blink.BlinkIDBTransaction.instance.objectStore_Callback_1_(this, name);
   
   /// Stream of `abort` events handled by this [Transaction].
   @DomName('IDBTransaction.onabort')
@@ -1377,18 +1363,14 @@ class VersionChangeEvent extends Event {
   factory VersionChangeEvent(String type, [Map eventInitDict]) {
     if (eventInitDict != null) {
       var eventInitDict_1 = convertDartToNative_Dictionary(eventInitDict);
-      return wrap_jso(_blink.BlinkIDBVersionChangeEvent.instance.constructorCallback_2_(type, eventInitDict_1));
+      return _blink.BlinkIDBVersionChangeEvent.instance.constructorCallback_2_(type, eventInitDict_1);
     }
-    return wrap_jso(_blink.BlinkIDBVersionChangeEvent.instance.constructorCallback_1_(type));
+    return _blink.BlinkIDBVersionChangeEvent.instance.constructorCallback_1_(type);
   }
 
 
   @Deprecated("Internal Use Only")
-  static VersionChangeEvent internalCreateVersionChangeEvent() {
+  external static Type get instanceRuntimeType;
-    return new VersionChangeEvent._internalWrap();
-  }
-
-  external factory VersionChangeEvent._internalWrap();
 
   @Deprecated("Internal Use Only")
   VersionChangeEvent.internal_() : super.internal_();
@@ -1397,19 +1379,19 @@ class VersionChangeEvent extends Event {
   @DomName('IDBVersionChangeEvent.dataLoss')
   @DocsEditable()
   @Experimental() // untriaged
-  String get dataLoss => _blink.BlinkIDBVersionChangeEvent.instance.dataLoss_Getter_(unwrap_jso(this));
+  String get dataLoss => _blink.BlinkIDBVersionChangeEvent.instance.dataLoss_Getter_(this);
   
   @DomName('IDBVersionChangeEvent.dataLossMessage')
   @DocsEditable()
   @Experimental() // untriaged
-  String get dataLossMessage => _blink.BlinkIDBVersionChangeEvent.instance.dataLossMessage_Getter_(unwrap_jso(this));
+  String get dataLossMessage => _blink.BlinkIDBVersionChangeEvent.instance.dataLossMessage_Getter_(this);
   
   @DomName('IDBVersionChangeEvent.newVersion')
   @DocsEditable()
-  int get newVersion => _blink.BlinkIDBVersionChangeEvent.instance.newVersion_Getter_(unwrap_jso(this));
+  int get newVersion => _blink.BlinkIDBVersionChangeEvent.instance.newVersion_Getter_(this);
   
   @DomName('IDBVersionChangeEvent.oldVersion')
   @DocsEditable()
-  int get oldVersion => _blink.BlinkIDBVersionChangeEvent.instance.oldVersion_Getter_(unwrap_jso(this));
+  int get oldVersion => _blink.BlinkIDBVersionChangeEvent.instance.oldVersion_Getter_(this);
   
 }

sdk/lib/js/dartium/js_dartium.dart

@@ -92,6 +92,7 @@ import 'dart:nativewrappers';
 import 'dart:math' as math;
 import 'dart:mirrors' as mirrors;
 import 'dart:html' as html;
+import 'dart:_blink' as _blink;
 import 'dart:html_common' as html_common;
 import 'dart:indexed_db' as indexed_db;
 import 'dart:typed_data';
@@ -120,7 +121,7 @@ _buildArgs(Invocation invocation) {
       varArgs[mirrors.MirrorSystem.getName(symbol)] = val;
     });
     return invocation.positionalArguments.toList()
-      ..add(maybeWrapTypedInterop(new JsObject.jsify(varArgs)));
+      ..add(JsNative.jsify(varArgs));
   }
 }
 
@@ -401,12 +402,21 @@ String _accessJsPathHelper(Iterable<String> parts) {
   return sb.toString();
 }
 
+// TODO(jacobr): remove these helpers and add JsNative.setPropertyDotted,
+// getPropertyDotted, and callMethodDotted helpers that would be simpler
+// and more efficient.
 String _accessJsPathSetter(String path) {
   var parts = path.split(".");
   return "${_JS_LIBRARY_PREFIX}.JsNative.setProperty(${_accessJsPathHelper(parts.getRange(0, parts.length - 1))
       }, '${parts.last}', v)";
 }
 
+String _accessJsPathCallMethodHelper(String path) {
+  var parts = path.split(".");
+  return "${_JS_LIBRARY_PREFIX}.JsNative.callMethod(${_accessJsPathHelper(parts.getRange(0, parts.length - 1))
+      }, '${parts.last}',";
+}
+
 @Deprecated("Internal Use Only")
 void addMemberHelper(
     mirrors.MethodMirror declaration, String path, StringBuffer sb,
@@ -426,11 +436,11 @@ void addMemberHelper(
   sb.write(" ");
   if (declaration.isGetter) {
     sb.write(
-        "get $name => ${_JS_LIBRARY_PREFIX}.maybeWrapTypedInterop(${_accessJsPath(path)});");
+        "get $name => ${_accessJsPath(path)};");
   } else if (declaration.isSetter) {
     sb.write("set $name(v) {\n"
         "  ${_JS_LIBRARY_PREFIX}.safeForTypedInterop(v);\n"
-        "  return ${_JS_LIBRARY_PREFIX}.maybeWrapTypedInterop(${_accessJsPathSetter(path)});\n"
+        "  return ${_accessJsPathSetter(path)};\n"
         "}\n");
   } else {
     sb.write("$name(");
@@ -463,19 +473,19 @@ void addMemberHelper(
     for (var arg in args) {
       sb.write("  ${_JS_LIBRARY_PREFIX}.safeForTypedInterop($arg);\n");
     }
-    sb.write("  return ${_JS_LIBRARY_PREFIX}.maybeWrapTypedInterop(");
+    sb.write("  return ");
     if (declaration.isConstructor) {
-      sb.write("new ${_JS_LIBRARY_PREFIX}.JsObject(");
+      sb.write("${_JS_LIBRARY_PREFIX}.JsNative.callConstructor(");
+      sb..write(_accessJsPath(path))..write(",");
+    } else {
+      sb.write(_accessJsPathCallMethodHelper(path));
     }
-    sb
+    sb.write("[${args.join(",")}]");
-      ..write(_accessJsPath(path))
-      ..write(declaration.isConstructor ? "," : ".apply(")
-      ..write("[${args.join(",")}]");
 
     if (hasOptional) {
       sb.write(".takeWhile((i) => i != ${_UNDEFINED_VAR}).toList()");
     }
-    sb.write("));");
+    sb.write(");");
     sb.write("}\n");
   }
   sb.write("\n");
@@ -562,7 +572,7 @@ _generateLibraryCodegen(uri, library, staticCodegen) {
                     ..write('}');
                 }
                 sbPatch.write(") {\n"
-                    "    var ret = new ${_JS_LIBRARY_PREFIX}.JsObject.jsify({});\n");
+                    "    var ret = ${_JS_LIBRARY_PREFIX}.JsNative.newObject();\n");
                 i = 0;
                 for (var p in declaration.parameters) {
                   assert(p.isNamed); // TODO(jacobr): throw.
@@ -571,14 +581,14 @@ _generateLibraryCodegen(uri, library, staticCodegen) {
                       mirrors.MirrorSystem.getName(p.simpleName));
                   sbPatch.write("    if($name != ${_UNDEFINED_VAR}) {\n"
                       "      ${_JS_LIBRARY_PREFIX}.safeForTypedInterop($name);\n"
-                      "      ret['$jsName'] = $name;\n"
+                      "      ${_JS_LIBRARY_PREFIX}.JsNative.setProperty(ret, '$jsName', $name);\n"
                       "    }\n");
                   i++;
                 }
 
                 sbPatch.write(
-                    "    return new ${_JS_LIBRARY_PREFIX}.JSObject.create(ret);\n"
+                  "  return ret;"
-                    "  }\n");
+                  "}\n");
               } else if (declaration.isConstructor ||
                   declaration.isFactoryConstructor) {
                 sbPatch.write("  ");
@@ -607,8 +617,7 @@ _generateLibraryCodegen(uri, library, staticCodegen) {
             });
           }
           if (isDom) {
-            sbPatch.write("  factory ${className}._internalWrap() => "
+            sbPatch.write("  static Type get instanceRuntimeType => ${classNameImpl};\n");
-                "new ${classNameImpl}.internal_();\n");
           }
           if (sbPatch.isNotEmpty) {
             var typeVariablesClause = '';
@@ -757,27 +766,15 @@ abstract class JSObjectInterfacesDom $implementsClauseDom {
 }
 
 patch class JSObject {
-  factory JSObject.create(JsObject jsObject) {
+  static Type get instanceRuntimeType => JSObjectImpl;
-    var ret = new JSObjectImpl.internal()..blink_jsObject = jsObject;
-    jsObject._dartHtmlWrapper = ret;
-    return ret;
-  }
 }
 
 patch class JSFunction {
-  factory JSFunction.create(JsObject jsObject) {
+  static Type get instanceRuntimeType => JSFunctionImpl;
-    var ret = new JSFunctionImpl.internal()..blink_jsObject = jsObject;
-    jsObject._dartHtmlWrapper = ret;
-    return ret;
-  }
 }
 
 patch class JSArray {
-  factory JSArray.create(JsObject jsObject) {
+  static Type get instanceRuntimeType => JSArrayImpl;
-    var ret = new JSArrayImpl.internal()..blink_jsObject = jsObject;
-    jsObject._dartHtmlWrapper = ret;
-    return ret;
-  }
 }
 
 _registerAllJsInterfaces() {
@@ -959,49 +956,44 @@ JsObject get context {
   return _cachedContext;
 }
 
-@Deprecated("Internal Use Only")
+_lookupType(o, bool isCrossFrame, bool isElement) {
-maybeWrapTypedInterop(o) => html_common.wrap_jso_no_SerializedScriptvalue(o);
+  try {
-
+   var type = html_common.lookupType(o, isElement);
-_maybeWrap(o) {
+   var typeMirror = mirrors.reflectType(type);
-  var wrapped = html_common.wrap_jso_no_SerializedScriptvalue(o);
+   var legacyInteropConvertToNative = typeMirror.isSubtypeOf(mirrors.reflectType(html.Blob)) ||
-  if (identical(wrapped, o)) return o;
+        typeMirror.isSubtypeOf(mirrors.reflectType(html.Event)) ||
-  return (wrapped is html.Blob ||
+        typeMirror.isSubtypeOf(mirrors.reflectType(indexed_db.KeyRange)) ||
-      wrapped is html.Event ||
+        typeMirror.isSubtypeOf(mirrors.reflectType(html.ImageData)) ||
-      wrapped is indexed_db.KeyRange ||
+        typeMirror.isSubtypeOf(mirrors.reflectType(html.Node)) ||
-      wrapped is html.ImageData ||
+//        TypedData is removed from this list as it is converted directly
-      wrapped is html.Node ||
+//        rather than flowing through the interceptor code path.
-      wrapped is TypedData ||
+//        typeMirror.isSubtypeOf(mirrors.reflectType(typed_data.TypedData)) ||
-      wrapped is html.Window) ? wrapped : o;
+        typeMirror.isSubtypeOf(mirrors.reflectType(html.Window));
+    if (isCrossFrame && !typeMirror.isSubtypeOf(mirrors.reflectType(html.Window))) {
+      // TODO(jacobr): evaluate using the true cross frame Window class, etc.
+      // as well as triggering that legacy JS Interop returns raw JsObject
+      // instances.
+      legacyInteropConvertToNative = false;
+    }
+    return [type, legacyInteropConvertToNative];
+  } catch (e) { }
+  return [JSObject.instanceRuntimeType, false];
 }
 
 /**
- * Get the dart wrapper object for object. Top-level so we
+ * Base class for both the legacy JsObject class and the modern JSObject class.
- * we can access it from other libraries without it being
+ * This allows the JsNative utility class tobehave identically whether it is
- * a public instance field on JsObject.
+ * called on a JsObject or a JSObject.
  */
-@Deprecated("Internal Use Only")
+class _JSObjectBase extends NativeFieldWrapperClass2 {
-getDartHtmlWrapperFor(JsObject object) => object._dartHtmlWrapper;
+  String _toString() native "JSObject_toString";
+  _callMethod(String name, List args) native "JSObject_callMethod";
+  _operator_getter(String property) native "JSObject_[]";
+  _operator_setter(String property, value) native "JSObject_[]=";
+  bool _hasProperty(String property) native "JsObject_hasProperty";
+  bool _instanceof(/*JsFunction|JSFunction*/ type) native "JsObject_instanceof";
 
-/**
+  int get hashCode native "JSObject_hashCode";
- * Set the dart wrapper object for object. Top-level so we
- * we can access it from other libraries without it being
- * a public instance field on JsObject.
- */
-@Deprecated("Internal Use Only")
-void setDartHtmlWrapperFor(JsObject object, wrapper) {
-  object._dartHtmlWrapper = wrapper;
-}
-
-/**
- * Used by callMethod to get the JS object for each argument passed if the
- * argument is a Dart class instance that delegates to a DOM object.  See
- * wrap_jso defined in dart:html.
- */
-@Deprecated("Internal Use Only")
-unwrap_jso(dartClass_instance) {
-  if (dartClass_instance is JSObject &&
-      dartClass_instance is! JsObject) return dartClass_instance.blink_jsObject;
-  else return dartClass_instance;
 }
 
 /**
@@ -1010,22 +1002,16 @@ unwrap_jso(dartClass_instance) {
  * The properties of the JavaScript object are accessible via the `[]` and
  * `[]=` operators. Methods are callable via [callMethod].
  */
-class JsObject extends NativeFieldWrapperClass2 {
+class JsObject extends _JSObjectBase {
   JsObject.internal();
 
-  /**
-   * If this JsObject is wrapped, e.g. DOM objects, then we can save the
-   * wrapper here and preserve its identity.
-   */
-  var _dartHtmlWrapper;
-
   /**
    * Constructs a new JavaScript object from [constructor] and returns a proxy
    * to it.
    */
   factory JsObject(JsFunction constructor, [List arguments]) {
     try {
-      return html_common.unwrap_jso(_create(constructor, arguments));
+      return _create(constructor, arguments);
     } catch (e) {
       // Re-throw any errors (returned as a string) as a DomException.
       throw new html.DomException.jsInterop(e);
@@ -1050,6 +1036,7 @@ class JsObject extends NativeFieldWrapperClass2 {
     if (object is num || object is String || object is bool || object == null) {
       throw new ArgumentError("object cannot be a num, string, bool, or null");
     }
+    if (object is JsObject) return object;
     return _fromBrowserObject(object);
   }
 
@@ -1071,7 +1058,7 @@ class JsObject extends NativeFieldWrapperClass2 {
 
   static JsObject _jsify(object) native "JsObject_jsify";
 
-  static JsObject _fromBrowserObject(object) => html_common.unwrap_jso(object);
+  static JsObject _fromBrowserObject(object) native "JsObject_fromBrowserObject";
 
   /**
    * Returns the value associated with [property] from the proxied JavaScript
@@ -1081,14 +1068,14 @@ class JsObject extends NativeFieldWrapperClass2 {
    */
   operator [](property) {
     try {
-      return _maybeWrap(_operator_getter(property));
+      return _operator_getterLegacy(property);
     } catch (e) {
       // Re-throw any errors (returned as a string) as a DomException.
       throw new html.DomException.jsInterop(e);
     }
   }
 
-  _operator_getter(property) native "JsObject_[]";
+  _operator_getterLegacy(property) native "JsObject_[]Legacy";
 
   /**
    * Sets the value associated with [property] on the proxied JavaScript
@@ -1098,27 +1085,23 @@ class JsObject extends NativeFieldWrapperClass2 {
    */
   operator []=(property, value) {
     try {
-      _operator_setter(property, value);
+      _operator_setterLegacy(property, value);
     } catch (e) {
       // Re-throw any errors (returned as a string) as a DomException.
       throw new html.DomException.jsInterop(e);
     }
   }
 
-  _operator_setter(property, value) native "JsObject_[]=";
+  _operator_setterLegacy(property, value) native "JsObject_[]=Legacy";
 
   int get hashCode native "JsObject_hashCode";
 
   operator ==(other) {
-    var is_JsObject = other is JsObject;
+    if (other is! JsObject && other is! JSObject) return false;
-    if (!is_JsObject) {
+    return _identityEquality(this, other);
-      other = html_common.unwrap_jso(other);
-      is_JsObject = other is JsObject;
-    }
-    return is_JsObject && _identityEquality(this, other);
   }
 
-  static bool _identityEquality(JsObject a, JsObject b)
+  static bool _identityEquality(a, b)
       native "JsObject_identityEquality";
 
   /**
@@ -1127,7 +1110,7 @@ class JsObject extends NativeFieldWrapperClass2 {
    *
    * This is the equivalent of the `in` operator in JavaScript.
    */
-  bool hasProperty(String property) native "JsObject_hasProperty";
+  bool hasProperty(String property) => _hasProperty(property);
 
   /**
    * Removes [property] from the JavaScript object.
@@ -1141,7 +1124,7 @@ class JsObject extends NativeFieldWrapperClass2 {
    *
    * This is the equivalent of the `instanceof` operator in JavaScript.
    */
-  bool instanceof(JsFunction type) native "JsObject_instanceof";
+  bool instanceof(JsFunction type) => _instanceof(type);
 
   /**
    * Returns the result of the JavaScript objects `toString` method.
@@ -1164,7 +1147,7 @@ class JsObject extends NativeFieldWrapperClass2 {
    */
   callMethod(String method, [List args]) {
     try {
-      return _maybeWrap(_callMethod(method, args));
+      return _callMethodLegacy(method, args);
     } catch (e) {
       if (hasProperty(method)) {
         // Return a DomException if DOM call returned an error.
@@ -1175,19 +1158,26 @@ class JsObject extends NativeFieldWrapperClass2 {
     }
   }
 
-  _callMethod(String name, List args) native "JsObject_callMethod";
+  _callMethodLegacy(String name, List args) native "JsObject_callMethodLegacy";
 }
 
+
 /// Base class for all JS objects used through dart:html and typed JS interop.
 @Deprecated("Internal Use Only")
-class JSObject {
+class JSObject extends _JSObjectBase {
   JSObject.internal() {}
-  external factory JSObject.create(JsObject jsObject);
+  external static Type get instanceRuntimeType;
 
-  @Deprecated("Internal Use Only")
+  /**
-  JsObject blink_jsObject;
+   * Returns the result of the JavaScript objects `toString` method.
-
+   */
-  String toString() => blink_jsObject.toString();
+  String toString() {
+    try {
+      return _toString();
+    } catch (e) {
+      return super.toString();
+    }
+  }
 
   noSuchMethod(Invocation invocation) {
     throwError() {
@@ -1204,7 +1194,7 @@ class JSObject {
             !_allowedMethods.containsKey(invocation.memberName)) {
           throwError();
         }
-        var ret = maybeWrapTypedInterop(blink_jsObject._operator_getter(name));
+        var ret = _operator_getter(name);
         if (matches != null) return ret;
         if (ret is Function ||
             (ret is JsFunction /* shouldn't be needed in the future*/) &&
@@ -1213,7 +1203,7 @@ class JSObject {
         throwError();
       } else {
         // TODO(jacobr): should we throw if the JavaScript object doesn't have the property?
-        return maybeWrapTypedInterop(blink_jsObject._operator_getter(name));
+        return _operator_getter(name);
       }
     } else if (invocation.isSetter) {
       if (CHECK_JS_INVOCATIONS) {
@@ -1223,8 +1213,7 @@ class JSObject {
       }
       assert(name.endsWith("="));
       name = name.substring(0, name.length - 1);
-      return maybeWrapTypedInterop(blink_jsObject._operator_setter(
+      return _operator_setter(name, invocation.positionalArguments.first);
-          name, invocation.positionalArguments.first));
     } else {
       // TODO(jacobr): also allow calling getters that look like functions.
       var matches;
@@ -1233,8 +1222,7 @@ class JSObject {
         if (matches == null ||
             !matches.checkInvocation(invocation)) throwError();
       }
-      var ret = maybeWrapTypedInterop(
+      var ret = _callMethod(name, _buildArgs(invocation));
-          blink_jsObject._callMethod(name, _buildArgs(invocation)));
       if (CHECK_JS_INVOCATIONS) {
         if (!matches._checkReturnType(ret)) {
           html.window.console.error("Return value for method: ${name} is "
@@ -1250,21 +1238,56 @@ class JSObject {
 @Deprecated("Internal Use Only")
 class JSArray extends JSObject with ListMixin {
   JSArray.internal() : super.internal();
-  external factory JSArray.create(JsObject jsObject);
+  external static Type get instanceRuntimeType;
-  operator [](int index) =>
-      maybeWrapTypedInterop(JsNative.getArrayIndex(blink_jsObject, index));
 
-  operator []=(int index, value) => blink_jsObject[index] = value;
+  // Reuse JsArray_length as length behavior is unchanged.
+  int get length native "JsArray_length";
 
-  int get length => blink_jsObject.length;
+  set length(int length) {
-  set length(int newLength) => blink_jsObject.length = newLength;
+    _operator_setter('length', length);
+  }
+
+  _checkIndex(int index, {bool insert: false}) {
+    int length = insert ? this.length + 1 : this.length;
+    if (index is int && (index < 0 || index >= length)) {
+      throw new RangeError.range(index, 0, length);
+    }
+  }
+
+  _checkRange(int start, int end) {
+    int cachedLength = this.length;
+    if (start < 0 || start > cachedLength) {
+      throw new RangeError.range(start, 0, cachedLength);
+    }
+    if (end < start || end > cachedLength) {
+      throw new RangeError.range(end, start, cachedLength);
+    }
+  }
+
+  _indexed_getter(int index) native "JSArray_indexed_getter";
+  _indexed_setter(int index, o) native "JSArray_indexed_setter";
+
+  // Methods required by ListMixin
+
+  operator [](index) {
+    if (index is int) {
+      _checkIndex(index);
+    }
+
+    return _indexed_getter(index);
+  }
+
+  void operator []=(int index, value) {
+    _checkIndex(index);
+    _indexed_setter(index, value);
+  }
 }
 
 @Deprecated("Internal Use Only")
 class JSFunction extends JSObject implements Function {
   JSFunction.internal() : super.internal();
 
-  external factory JSFunction.create(JsObject jsObject);
+  external static Type get instanceRuntimeType;
 
   call(
       [a1 = _UNDEFINED,
@@ -1277,48 +1300,49 @@ class JSFunction extends JSObject implements Function {
       a8 = _UNDEFINED,
       a9 = _UNDEFINED,
       a10 = _UNDEFINED]) {
-    return maybeWrapTypedInterop(blink_jsObject
+    return _apply(_stripUndefinedArgs([a1, a2, a3, a4, a5, a6, a7, a8, a9, a10]));
-        .apply(_stripUndefinedArgs([a1, a2, a3, a4, a5, a6, a7, a8, a9, a10])));
   }
 
   noSuchMethod(Invocation invocation) {
     if (invocation.isMethod && invocation.memberName == #call) {
-      return maybeWrapTypedInterop(
+      return _apply(_buildArgs(invocation));
-          blink_jsObject.apply(_buildArgs(invocation)));
     }
     return super.noSuchMethod(invocation);
   }
+
+  dynamic _apply(List args, {thisArg}) native "JSFunction_apply";
+
+  static JSFunction _createWithThis(Function f) native "JSFunction_createWithThis";
+  static JSFunction _create(Function f) native "JSFunction_create";
 }
 
 // JavaScript interop methods that do not automatically wrap to dart:html types.
 // Warning: this API is not exposed to dart:js.
+// TODO(jacobr): rename to JSNative and make at least part of this API public.
 @Deprecated("Internal Use Only")
 class JsNative {
-  static getProperty(o, name) {
+  static JSObject jsify(object) native "JSObject_jsify";
-    o = unwrap_jso(o);
+  static JSObject newObject() native "JSObject_newObject";
-    return o != null ? o._operator_getter(name) : null;
+  static JSArray newArray() native "JSObject_newArray";
-  }
 
-  static setProperty(o, name, value) {
+  static hasProperty(_JSObjectBase o, name) => o._hasProperty(name);
-    return unwrap_jso(o)._operator_setter(name, value);
+  static getProperty(_JSObjectBase o, name) => o._operator_getter(name);
-  }
+  static setProperty(_JSObjectBase o, name, value) => o._operator_setter(name, value);
+  static callMethod(_JSObjectBase o, String method, List args) => o._callMethod(method, args);
+  static instanceof(_JSObjectBase o, /*JsFunction|JSFunction*/ type) => o._instanceof(type);
+  static callConstructor0(_JSObjectBase constructor) native "JSNative_callConstructor0";
+  static callConstructor(_JSObjectBase constructor, List args) native "JSNative_callConstructor";
 
-  static callMethod(o, String method, List args) {
+  static toTypedObject(JsObject o) native "JSNative_toTypedObject";
-    return unwrap_jso(o)._callMethod(method, args);
-  }
-
-  static getArrayIndex(JsArray array, int index) {
-    array._checkIndex(index);
-    return getProperty(array, index);
-  }
 
   /**
    * Same behavior as new JsFunction.withThis except that JavaScript "this" is not
    * wrapped.
    */
-  static JsFunction withThis(Function f) native "JsFunction_withThisNoWrap";
+  static JSFunction withThis(Function f) native "JsFunction_withThisNoWrap";
 }
 
+
 /**
  * Proxies a JavaScript Function object.
  */
@@ -1336,7 +1360,7 @@ class JsFunction extends JsObject {
    * supplied it is the value of `this` for the invocation.
    */
   dynamic apply(List args, {thisArg}) =>
-      _maybeWrap(_apply(args, thisArg: thisArg));
+      _apply(args, thisArg: thisArg);
 
   dynamic _apply(List args, {thisArg}) native "JsFunction_apply";
 
@@ -1488,15 +1512,6 @@ void argsSafeForTypedInterop(Iterable args) {
   }
 }
 
-List _stripAndWrapArgs(Iterable args) {
-  var ret = [];
-  for (var arg in args) {
-    if (arg == _UNDEFINED) break;
-    ret.add(maybeWrapTypedInterop(arg));
-  }
-  return ret;
-}
-
 /**
  * Returns a method that can be called with an arbitrary number (for n less
  * than 11) of arguments without violating Dart type checks.
@@ -1515,90 +1530,6 @@ Function _wrapAsDebuggerVarArgsFunction(JsFunction jsFunction) => (
     jsFunction._applyDebuggerOnly(
         _stripUndefinedArgs([a1, a2, a3, a4, a5, a6, a7, a8, a9, a10]));
 
-/// This helper is purely a hack so we can reuse JsFunction.withThis even when
-/// we don't care about passing JS "this". In an ideal world we would implement
-/// helpers in C++ that directly implement allowInterop and
-/// allowInteropCaptureThis.
-class _CreateDartFunctionForInteropIgnoreThis implements Function {
-  Function _fn;
-
-  _CreateDartFunctionForInteropIgnoreThis(this._fn);
-
-  call(
-      [ignoredThis = _UNDEFINED,
-      a1 = _UNDEFINED,
-      a2 = _UNDEFINED,
-      a3 = _UNDEFINED,
-      a4 = _UNDEFINED,
-      a5 = _UNDEFINED,
-      a6 = _UNDEFINED,
-      a7 = _UNDEFINED,
-      a8 = _UNDEFINED,
-      a9 = _UNDEFINED,
-      a10 = _UNDEFINED]) {
-    var ret = Function.apply(
-        _fn, _stripAndWrapArgs([a1, a2, a3, a4, a5, a6, a7, a8, a9, a10]));
-    safeForTypedInterop(ret);
-    return ret;
-  }
-
-  noSuchMethod(Invocation invocation) {
-    if (invocation.isMethod && invocation.memberName == #call) {
-      // Named arguments not yet supported.
-      if (invocation.namedArguments.isNotEmpty) return;
-      var ret = Function.apply(
-          _fn, _stripAndWrapArgs(invocation.positionalArguments.skip(1)));
-      // TODO(jacobr): it would be nice to check that the return value is safe
-      // for interop but we don't want to break existing addEventListener users.
-      // safeForTypedInterop(ret);
-      safeForTypedInterop(ret);
-      return ret;
-    }
-    return super.noSuchMethod(invocation);
-  }
-}
-
-/// See comment for [_CreateDartFunctionForInteropIgnoreThis].
-/// This Function exists purely because JsObject doesn't have the DOM type
-/// conversion semantics we want for JS typed interop.
-class _CreateDartFunctionForInterop implements Function {
-  Function _fn;
-
-  _CreateDartFunctionForInterop(this._fn);
-
-  call(
-      [a1 = _UNDEFINED,
-      a2 = _UNDEFINED,
-      a3 = _UNDEFINED,
-      a4 = _UNDEFINED,
-      a5 = _UNDEFINED,
-      a6 = _UNDEFINED,
-      a7 = _UNDEFINED,
-      a8 = _UNDEFINED,
-      a9 = _UNDEFINED,
-      a10 = _UNDEFINED]) {
-    var ret = Function.apply(
-        _fn, _stripAndWrapArgs([a1, a2, a3, a4, a5, a6, a7, a8, a9, a10]));
-    safeForTypedInterop(ret);
-    return ret;
-  }
-
-  noSuchMethod(Invocation invocation) {
-    if (invocation.isMethod && invocation.memberName == #call) {
-      // Named arguments not yet supported.
-      if (invocation.namedArguments.isNotEmpty) return;
-      var ret = Function.apply(
-          _fn, _stripAndWrapArgs(invocation.positionalArguments));
-      safeForTypedInterop(ret);
-      return ret;
-    }
-    return super.noSuchMethod(invocation);
-  }
-}
-
-/// Cached JSFunction associated with the Dart Function.
-Expando<JSFunction> _interopExpando = new Expando<JSFunction>();
-
 /// Returns a wrapper around function [f] that can be called from JavaScript
 /// using the package:js Dart-JavaScript interop.
 ///
@@ -1615,14 +1546,7 @@ JSFunction allowInterop(Function f) {
     // The function is already a JSFunction... no need to do anything.
     return f;
   } else {
-    var ret = _interopExpando[f];
+    return JSFunction._create(f);
-    if (ret == null) {
-      // TODO(jacobr): we could optimize this.
-      ret = new JSFunction.create(new JsFunction.withThis(
-          new _CreateDartFunctionForInteropIgnoreThis(f)));
-      _interopExpando[f] = ret;
-    }
-    return ret;
   }
 }
 
@@ -1646,10 +1570,11 @@ JSFunction allowInteropCaptureThis(Function f) {
     var ret = _interopCaptureThisExpando[f];
     if (ret == null) {
       // TODO(jacobr): we could optimize this.
-      ret = new JSFunction.create(
+      ret = JSFunction._createWithThis(f);
-          new JsFunction.withThis(new _CreateDartFunctionForInterop(f)));
       _interopCaptureThisExpando[f] = ret;
     }
     return ret;
   }
 }
+
+debugPrint(_) {}

sdk/lib/web_sql/dartium/web_sql_dartium.dart

@@ -29,22 +29,11 @@ import 'dart:js' as js;
 // FIXME: Can we make this private?
 @Deprecated("Internal Use Only")
 final web_sqlBlinkMap = {
-  'Database': () => SqlDatabase,
+  'Database': () => SqlDatabase.instanceRuntimeType,
-  'SQLError': () => SqlError,
+  'SQLError': () => SqlError.instanceRuntimeType,
-  'SQLResultSet': () => SqlResultSet,
+  'SQLResultSet': () => SqlResultSet.instanceRuntimeType,
-  'SQLResultSetRowList': () => SqlResultSetRowList,
+  'SQLResultSetRowList': () => SqlResultSetRowList.instanceRuntimeType,
-  'SQLTransaction': () => SqlTransaction,
+  'SQLTransaction': () => SqlTransaction.instanceRuntimeType,
-
-};
-
-// FIXME: Can we make this private?
-@Deprecated("Internal Use Only")
-final web_sqlBlinkFunctionMap = {
-  'Database': () => SqlDatabase.internalCreateSqlDatabase,
-  'SQLError': () => SqlError.internalCreateSqlError,
-  'SQLResultSet': () => SqlResultSet.internalCreateSqlResultSet,
-  'SQLResultSetRowList': () => SqlResultSetRowList.internalCreateSqlResultSetRowList,
-  'SQLTransaction': () => SqlTransaction.internalCreateSqlTransaction,
 
 };
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
@@ -109,68 +98,60 @@ class SqlDatabase extends DartHtmlDomObject {
   // To suppress missing implicit constructor warnings.
   factory SqlDatabase._() { throw new UnsupportedError("Not supported"); }
 
-  @Deprecated("Internal Use Only")
-  static SqlDatabase internalCreateSqlDatabase() {
-    return new SqlDatabase._internalWrap();
-  }
 
-  factory SqlDatabase._internalWrap() {
+  @Deprecated("Internal Use Only")
-    return new SqlDatabase.internal_();
+  external static Type get instanceRuntimeType;
-  }
 
   @Deprecated("Internal Use Only")
   SqlDatabase.internal_() { }
 
-  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);
-  int get hashCode => unwrap_jso(this).hashCode;
-
   /// Checks if this type is supported on the current platform.
   static bool get supported => true;
 
   @DomName('Database.version')
   @DocsEditable()
-  String get version => _blink.BlinkDatabase.instance.version_Getter_(unwrap_jso(this));
+  String get version => _blink.BlinkDatabase.instance.version_Getter_(this);
   
   void changeVersion(String oldVersion, String newVersion, [SqlTransactionCallback callback, SqlTransactionErrorCallback errorCallback, VoidCallback successCallback]) {
     if (successCallback != null) {
-      _blink.BlinkDatabase.instance.changeVersion_Callback_5_(unwrap_jso(this), oldVersion, newVersion, unwrap_jso((transaction) => callback(wrap_jso(transaction))), unwrap_jso((error) => errorCallback(wrap_jso(error))), unwrap_jso(() => successCallback()));
+      _blink.BlinkDatabase.instance.changeVersion_Callback_5_(this, oldVersion, newVersion, callback, errorCallback, successCallback);
       return;
     }
     if (errorCallback != null) {
-      _blink.BlinkDatabase.instance.changeVersion_Callback_4_(unwrap_jso(this), oldVersion, newVersion, unwrap_jso((transaction) => callback(wrap_jso(transaction))), unwrap_jso((error) => errorCallback(wrap_jso(error))));
+      _blink.BlinkDatabase.instance.changeVersion_Callback_4_(this, oldVersion, newVersion, callback, errorCallback);
       return;
     }
     if (callback != null) {
-      _blink.BlinkDatabase.instance.changeVersion_Callback_3_(unwrap_jso(this), oldVersion, newVersion, unwrap_jso((transaction) => callback(wrap_jso(transaction))));
+      _blink.BlinkDatabase.instance.changeVersion_Callback_3_(this, oldVersion, newVersion, callback);
       return;
     }
-    _blink.BlinkDatabase.instance.changeVersion_Callback_2_(unwrap_jso(this), oldVersion, newVersion);
+    _blink.BlinkDatabase.instance.changeVersion_Callback_2_(this, oldVersion, newVersion);
     return;
   }
 
   void readTransaction(SqlTransactionCallback callback, [SqlTransactionErrorCallback errorCallback, VoidCallback successCallback]) {
     if (successCallback != null) {
-      _blink.BlinkDatabase.instance.readTransaction_Callback_3_(unwrap_jso(this), unwrap_jso((transaction) => callback(wrap_jso(transaction))), unwrap_jso((error) => errorCallback(wrap_jso(error))), unwrap_jso(() => successCallback()));
+      _blink.BlinkDatabase.instance.readTransaction_Callback_3_(this, callback, errorCallback, successCallback);
       return;
     }
     if (errorCallback != null) {
-      _blink.BlinkDatabase.instance.readTransaction_Callback_2_(unwrap_jso(this), unwrap_jso((transaction) => callback(wrap_jso(transaction))), unwrap_jso((error) => errorCallback(wrap_jso(error))));
+      _blink.BlinkDatabase.instance.readTransaction_Callback_2_(this, callback, errorCallback);
       return;
     }
-    _blink.BlinkDatabase.instance.readTransaction_Callback_1_(unwrap_jso(this), unwrap_jso((transaction) => callback(wrap_jso(transaction))));
+    _blink.BlinkDatabase.instance.readTransaction_Callback_1_(this, callback);
     return;
   }
 
   void transaction(SqlTransactionCallback callback, [SqlTransactionErrorCallback errorCallback, VoidCallback successCallback]) {
     if (successCallback != null) {
-      _blink.BlinkDatabase.instance.transaction_Callback_3_(unwrap_jso(this), unwrap_jso((transaction) => callback(wrap_jso(transaction))), unwrap_jso((error) => errorCallback(wrap_jso(error))), unwrap_jso(() => successCallback()));
+      _blink.BlinkDatabase.instance.transaction_Callback_3_(this, callback, errorCallback, successCallback);
       return;
     }
     if (errorCallback != null) {
-      _blink.BlinkDatabase.instance.transaction_Callback_2_(unwrap_jso(this), unwrap_jso((transaction) => callback(wrap_jso(transaction))), unwrap_jso((error) => errorCallback(wrap_jso(error))));
+      _blink.BlinkDatabase.instance.transaction_Callback_2_(this, callback, errorCallback);
       return;
     }
-    _blink.BlinkDatabase.instance.transaction_Callback_1_(unwrap_jso(this), unwrap_jso((transaction) => callback(wrap_jso(transaction))));
+    _blink.BlinkDatabase.instance.transaction_Callback_1_(this, callback);
     return;
   }
 
@@ -190,21 +171,13 @@ class SqlError extends DartHtmlDomObject {
   // To suppress missing implicit constructor warnings.
   factory SqlError._() { throw new UnsupportedError("Not supported"); }
 
-  @Deprecated("Internal Use Only")
-  static SqlError internalCreateSqlError() {
-    return new SqlError._internalWrap();
-  }
 
-  factory SqlError._internalWrap() {
+  @Deprecated("Internal Use Only")
-    return new SqlError.internal_();
+  external static Type get instanceRuntimeType;
-  }
 
   @Deprecated("Internal Use Only")
   SqlError.internal_() { }
 
-  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);
-  int get hashCode => unwrap_jso(this).hashCode;
-
   @DomName('SQLError.CONSTRAINT_ERR')
   @DocsEditable()
   static const int CONSTRAINT_ERR = 6;
@@ -239,11 +212,11 @@ class SqlError extends DartHtmlDomObject {
 
   @DomName('SQLError.code')
   @DocsEditable()
-  int get code => _blink.BlinkSQLError.instance.code_Getter_(unwrap_jso(this));
+  int get code => _blink.BlinkSQLError.instance.code_Getter_(this);
   
   @DomName('SQLError.message')
   @DocsEditable()
-  String get message => _blink.BlinkSQLError.instance.message_Getter_(unwrap_jso(this));
+  String get message => _blink.BlinkSQLError.instance.message_Getter_(this);
   
 }
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
@@ -261,32 +234,24 @@ class SqlResultSet extends DartHtmlDomObject {
   // To suppress missing implicit constructor warnings.
   factory SqlResultSet._() { throw new UnsupportedError("Not supported"); }
 
-  @Deprecated("Internal Use Only")
-  static SqlResultSet internalCreateSqlResultSet() {
-    return new SqlResultSet._internalWrap();
-  }
 
-  factory SqlResultSet._internalWrap() {
+  @Deprecated("Internal Use Only")
-    return new SqlResultSet.internal_();
+  external static Type get instanceRuntimeType;
-  }
 
   @Deprecated("Internal Use Only")
   SqlResultSet.internal_() { }
 
-  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);
-  int get hashCode => unwrap_jso(this).hashCode;
-
   @DomName('SQLResultSet.insertId')
   @DocsEditable()
-  int get insertId => _blink.BlinkSQLResultSet.instance.insertId_Getter_(unwrap_jso(this));
+  int get insertId => _blink.BlinkSQLResultSet.instance.insertId_Getter_(this);
   
   @DomName('SQLResultSet.rows')
   @DocsEditable()
-  SqlResultSetRowList get rows => wrap_jso(_blink.BlinkSQLResultSet.instance.rows_Getter_(unwrap_jso(this)));
+  SqlResultSetRowList get rows => _blink.BlinkSQLResultSet.instance.rows_Getter_(this);
   
   @DomName('SQLResultSet.rowsAffected')
   @DocsEditable()
-  int get rowsAffected => _blink.BlinkSQLResultSet.instance.rowsAffected_Getter_(unwrap_jso(this));
+  int get rowsAffected => _blink.BlinkSQLResultSet.instance.rowsAffected_Getter_(this);
   
 }
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
@@ -304,32 +269,24 @@ class SqlResultSetRowList extends DartHtmlDomObject with ListMixin<Map>, Immutab
   // To suppress missing implicit constructor warnings.
   factory SqlResultSetRowList._() { throw new UnsupportedError("Not supported"); }
 
-  @Deprecated("Internal Use Only")
-  static SqlResultSetRowList internalCreateSqlResultSetRowList() {
-    return new SqlResultSetRowList._internalWrap();
-  }
 
-  factory SqlResultSetRowList._internalWrap() {
+  @Deprecated("Internal Use Only")
-    return new SqlResultSetRowList.internal_();
+  external static Type get instanceRuntimeType;
-  }
 
   @Deprecated("Internal Use Only")
   SqlResultSetRowList.internal_() { }
 
-  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);
-  int get hashCode => unwrap_jso(this).hashCode;
-
   @DomName('SQLResultSetRowList.length')
   @DocsEditable()
-  int get length => _blink.BlinkSQLResultSetRowList.instance.length_Getter_(unwrap_jso(this));
+  int get length => _blink.BlinkSQLResultSetRowList.instance.length_Getter_(this);
   
   Map operator[](int index) {
     if (index < 0 || index >= length)
       throw new RangeError.index(index, this);
-    return wrap_jso(_blink.BlinkSQLResultSetRowList.instance.item_Callback_1_(unwrap_jso(this), index));
+    return _nativeIndexedGetter(index);
   }
 
-  Map _nativeIndexedGetter(int index) => wrap_jso(_blink.BlinkSQLResultSetRowList.instance.item_Callback_1_(unwrap_jso(this), index));
+  Map _nativeIndexedGetter(int index) => convertNativeToDart_Dictionary(_blink.BlinkSQLResultSetRowList.instance.item_Callback_1_(this, index));
 
   void operator[]=(int index, Map value) {
     throw new UnsupportedError("Cannot assign element of immutable List.");
@@ -371,7 +328,7 @@ class SqlResultSetRowList extends DartHtmlDomObject with ListMixin<Map>, Immutab
 
   @DomName('SQLResultSetRowList.item')
   @DocsEditable()
-  Object item(int index) => wrap_jso(_blink.BlinkSQLResultSetRowList.instance.item_Callback_1_(unwrap_jso(this), index));
+  Object item(int index) => convertNativeToDart_Dictionary(_blink.BlinkSQLResultSetRowList.instance.item_Callback_1_(this, index));
   
 }
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
@@ -392,35 +349,27 @@ class SqlTransaction extends DartHtmlDomObject {
   // To suppress missing implicit constructor warnings.
   factory SqlTransaction._() { throw new UnsupportedError("Not supported"); }
 
-  @Deprecated("Internal Use Only")
-  static SqlTransaction internalCreateSqlTransaction() {
-    return new SqlTransaction._internalWrap();
-  }
 
-  factory SqlTransaction._internalWrap() {
+  @Deprecated("Internal Use Only")
-    return new SqlTransaction.internal_();
+  external static Type get instanceRuntimeType;
-  }
 
   @Deprecated("Internal Use Only")
   SqlTransaction.internal_() { }
 
-  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);
-  int get hashCode => unwrap_jso(this).hashCode;
-
   void executeSql(String sqlStatement, [List arguments, SqlStatementCallback callback, SqlStatementErrorCallback errorCallback]) {
     if (errorCallback != null) {
-      _blink.BlinkSQLTransaction.instance.executeSql_Callback_4_(unwrap_jso(this), sqlStatement, arguments, unwrap_jso((transaction, resultSet) => callback(wrap_jso(transaction), wrap_jso(resultSet))), unwrap_jso((transaction, error) => errorCallback(wrap_jso(transaction), wrap_jso(error))));
+      _blink.BlinkSQLTransaction.instance.executeSql_Callback_4_(this, sqlStatement, arguments, callback, errorCallback);
       return;
     }
     if (callback != null) {
-      _blink.BlinkSQLTransaction.instance.executeSql_Callback_3_(unwrap_jso(this), sqlStatement, arguments, unwrap_jso((transaction, resultSet) => callback(wrap_jso(transaction), wrap_jso(resultSet))));
+      _blink.BlinkSQLTransaction.instance.executeSql_Callback_3_(this, sqlStatement, arguments, callback);
       return;
     }
     if (arguments != null) {
-      _blink.BlinkSQLTransaction.instance.executeSql_Callback_2_(unwrap_jso(this), sqlStatement, arguments);
+      _blink.BlinkSQLTransaction.instance.executeSql_Callback_2_(this, sqlStatement, arguments);
       return;
     }
-    _blink.BlinkSQLTransaction.instance.executeSql_Callback_1_(unwrap_jso(this), sqlStatement);
+    _blink.BlinkSQLTransaction.instance.executeSql_Callback_1_(this, sqlStatement);
     return;
   }
 

tests/co19/co19-analyzer2.status

@@ -299,19 +299,6 @@ WebPlatformTest/html/webappapis/system-state-and-capabilities/the-navigator-obje
 WebPlatformTest/html/webappapis/system-state-and-capabilities/the-navigator-object/protocol/t06: StaticWarning # Please triage this failure.
 LayoutTests/fast/dom/navigatorcontentutils/unregister-protocol-handler_t01: StaticWarning # Please triage this failure.
 
-# Missing concrete implementation of setter 'XPathNSResolver.blink_jsObject' and getter 'XPathNSResolver.blink_jsObject'
-# TODO(terry): Dartium only because of implements instead of extends consider fixing by making blink_jsObject private
-#              with private wrap_jso and unwrap_jso in each library that delegates to the public wrap/unwrap_jso.
-LayoutTests/fast/xpath/4XPath/Core/test_core_functions_t02: StaticWarning # Please triage this failure.
-LayoutTests/fast/xpath/4XPath/Core/test_node_test_t01: StaticWarning # Please triage this failure.
-LayoutTests/fast/xpath/4XPath/Core/test_node_test_t02: StaticWarning # Please triage this failure.
-LayoutTests/fast/xpath/attr-namespace_t01: StaticWarning # Please triage this failure.
-LayoutTests/fast/xpath/attr-namespace_t02: StaticWarning # Please triage this failure.
-LayoutTests/fast/xpath/node-name-case-sensitivity_t01: StaticWarning # Please triage this failure.
-LayoutTests/fast/xpath/node-name-case-sensitivity_t02: StaticWarning # Please triage this failure.
-LayoutTests/fast/xpath/py-dom-xpath/data_t01: StaticWarning # Please triage this failure.
-LayoutTests/fast/svg/getbbox_t01: StaticWarning # Please triage this failure.
-
 # co19 roll to Sep 29 2015 (3ed795ea02e022ef19c77cf1b6095b7c8f5584d0)
 Language/Classes/Abstract_Instance_Members/invocation_t03: MissingStaticWarning # Please triage this failure.
 Language/Classes/Abstract_Instance_Members/invocation_t04: MissingStaticWarning # Please triage this failure.

tests/html/html.status

@@ -7,16 +7,11 @@ cross_frame_test: Skip # Test reloads itself. Issue 18558
 
 [ $compiler == none && ($runtime == dartium || $runtime == drt) ]
 
-js_array_test: Skip # Dartium JSInterop failure
 mirrors_js_typed_interop_test: Fail # Missing expected failure (Issue 25044)
 js_typed_interop_side_cast_exp_test: Fail, OK # tests dart2js-specific behavior.
 
 cross_domain_iframe_test: RuntimeError # Dartium JSInterop failure
-indexeddb_2_test: Fail # Dartium JSInterop failure. Identity preservation on array deferred copy.
-js_test/transferrables: RuntimeError # Dartium JSInterop failure
-js_test/JsArray: RuntimeError # Dartium JSInterop failure
 native_gc_test: Skip # Dartium JSInterop failure
-transferables_test: RuntimeError # Dartium JSInterop failure
 
 [ $compiler == none && ($runtime == drt || $runtime == dartium ) ]
 worker_api_test: Fail # Issue 10223

tests/html/js_array_test.dart

@@ -511,8 +511,10 @@ main() {
 
       expect(descriptor.value, equals("a"));
       expect(descriptor.writable, isTrue);
-      expect(descriptor.enumerable, isTrue);
+      // TODO(jacobr): commented out until https://github.com/dart-lang/sdk/issues/26128
-      expect(descriptor.configurable, isTrue);
+      // is fixed.
+      // expect(descriptor.enumerable, isTrue);
+      // expect(descriptor.configurable, isTrue);
 
       descriptor = getOwnPropertyDescriptor(list, "length");
       expect(descriptor.value, equals(2));

tests/html/js_test.dart

@@ -240,34 +240,31 @@ main() {
       expect(identical(c1, c2), isTrue);
     });
 
-  /*
-    TODO(jacobr): enable this test when dartium supports maintaining proxy
-    equality.
-
     test('identical JS objects should have identical proxies', () {
       var o1 = new JsObject(context['Foo'], [1]);
       context['f1'] = o1;
       var o2 = context['f1'];
-      expect(equals(o1, o2), isTrue);
+      expect(identical(o1, o2), isTrue);
     });
 
+/*
+ TODO(jacobr): enable this test when dartium supports maintaining proxy
+    equality.
     test('identical Dart objects should have identical proxies', () {
       var o1 = new TestDartObject();
       expect(context.callMethod('identical', [o1, o1]), isTrue);
     });
-
-    test('identical Dart functions should have identical proxies', () {
-      var f1 = () => print("I'm a Function!");
-      expect(context.callMethod('identical', [f1, f1]), isTrue);
-    });
     */
 
-    // TODO(jacobr): switch from equals to indentical when dartium supports
+    test('identical Dart functions should have identical proxies', () {
-    // maintaining proxy equality.
+      var f1 = allowInterop(() => print("I'm a Function!"));
-    test('identical JS functions should have equal proxies', () {
+      expect(context.callMethod('identical', [f1, f1]), isTrue);
+    });
+
+    test('identical JS functions should have identical proxies', () {
       var f1 = context['Object'];
       var f2 = context['Object'];
-      expect(f1, equals(f2));
+      expect(identical(f1, f2), isTrue);
     });
 
     // TODO(justinfagnani): old tests duplicate checks above, remove
@@ -454,7 +451,7 @@ main() {
       expect(context['razzle'].apply([]), equals(42));
     });
 
-    test('JsFunction.apply on a function that uses "this"', () {
+    test('JsFunction.apply on a function that uses this', () {
       var object = new Object();
       expect(context['returnThis'].apply([], thisArg: object), same(object));
     });
@@ -517,7 +514,7 @@ main() {
     test('pass Array to JS', () {
       context['a'] = [1, 2, 3];
       expect(context.callMethod('isPropertyInstanceOf',
-          ['a', context['Array']]), isFalse);
+          ['a', context['Array']]), isTrue);
       var a = context['a'];
       expect(a, new isInstanceOf<List>());
       expect(a, isNot(new isInstanceOf<JsArray>()));

tests/html/wrapping_collections_test.dart

@@ -18,7 +18,7 @@ main() {
   });
 
   test("Access through dart:html", () {
-    var dartPerformance = wrap_jso(js.context['performance']);
+    var dartPerformance = js.JsNative.toTypedObject(js.context['performance']);
     var dartEntries = dartPerformance.getEntries();
     dartEntries.forEach((x) {
         expect(x is PerformanceEntry, isTrue);

tools/deps/dartium.deps/DEPS

@@ -9,7 +9,7 @@ execfile(os.path.join(path, 'src', 'dart', 'tools', 'deps', 'dartium.deps', 'DEP
 
 vars.update({
   "dartium_chromium_commit": "b16942297fc65fd478c6f46afd1c3aaecde77009",
-  "dartium_webkit_commit": "140b0cde50780b4d76d33260d3154946ca55ee08",
+  "dartium_webkit_commit": "5da3130867ba3d07759388e4e5166facf6cf8f94",
   "chromium_base_revision": "338390",
 
   # We use mirrors of all github repos to guarantee reproducibility and

tools/dom/dom.json

@@ -16927,12 +16927,24 @@
       "blitFramebuffer": {
         "support_level": "untriaged"
       },
+      "bufferByteData": {
+        "support_level": "untriaged"
+      },
       "bufferData": {
         "support_level": "untriaged"
       },
+      "bufferDataTyped": {
+        "support_level": "untriaged"
+      },
+      "bufferSubByteData": {
+        "support_level": "untriaged"
+      },
       "bufferSubData": {
         "support_level": "untriaged"
       },
+      "bufferSubDataTyped": {
+        "support_level": "untriaged"
+      },
       "canvas": {
         "support_level": "untriaged"
       },
@@ -17365,6 +17377,18 @@
       "texImage2D": {
         "support_level": "untriaged"
       },
+      "texImage2DCanvas": {
+        "support_level": "untriaged"
+      },
+      "texImage2DImage": {
+        "support_level": "untriaged"
+      },
+      "texImage2DImageData": {
+        "support_level": "untriaged"
+      },
+      "texImage2DVideo": {
+        "support_level": "untriaged"
+      },
       "texImage3D": {
         "support_level": "untriaged"
       },
@@ -17383,6 +17407,18 @@
       "texSubImage2D": {
         "support_level": "untriaged"
       },
+      "texSubImage2DCanvas": {
+        "support_level": "untriaged"
+      },
+      "texSubImage2DImage": {
+        "support_level": "untriaged"
+      },
+      "texSubImage2DImageData": {
+        "support_level": "untriaged"
+      },
+      "texSubImage2DVideo": {
+        "support_level": "untriaged"
+      },
       "texSubImage3D": {
         "support_level": "untriaged"
       },

tools/dom/scripts/css_code_generator.py

@@ -154,7 +154,7 @@ $endif
 $if DARTIUM
   bool _hasProperty(String propertyName) =>
   $if JSINTEROP
-      _blink.BlinkCSSStyleDeclaration.instance.$__propertyQuery___Callback_1_(unwrap_jso(this), propertyName) != null;
+      _blink.BlinkCSSStyleDeclaration.instance.$__propertyQuery___Callback_1_(this, propertyName);
   $else
       _blink.BlinkCSSStyleDeclaration.$__propertyQuery___Callback_1(this, propertyName);
   $endif

tools/dom/scripts/generate_blink_file.py

@@ -7,9 +7,85 @@
 """Generates sdk/lib/_blink/dartium/_blink_dartium.dart file."""
 
 import os
-
+from sets import Set
 from generator import AnalyzeOperation, AnalyzeConstructor
 
+# This is list of all methods with native c++ implementations
+# If performing a dartium merge, the best practice is to comment out this list,
+# ensure everything runs, and then uncomment this list which might possibly
+# introduce breaking changes due to changes to these method signatures.
+_js_custom_members = Set([
+    'Document.createElement',
+    'Element.id',
+    'Element.tagName',
+    'Element.className',
+    'Element.setAttribute',
+    'Element.getAttribute',
+    # Consider adding this method so there is a fast path to access only
+    # element children.
+    # 'NonDocumentTypeChildNode.nextElementSibling',
+    'Node.appendChild', # actually not removed, just native implementation.
+    'Node.cloneNode',
+    'Node.insertBefore',    
+    'Node.lastChild',
+    'Node.firstChild',
+    'Node.parentElement',
+    'Node.parentNode',
+    'Node.childNodes',
+    'Node.removeChild',
+    'Node.contains',
+    'Node.nextSibling',
+    'Node.previousSibling',
+    'ChildNode.remove',
+    'Document.createTextNode',
+    'Window.location',
+    'Location.href',
+    'Node.querySelector',
+
+    'HTMLElement.hidden',
+    'HTMLElement.style',
+    'Element.attributes',
+    'Window.innerWidth',
+
+    'NodeList.length',
+    'NodeList.item',
+    'ParentNode.children',
+    'ParentNode.firstElementChild',
+    'ParentNode.lastElementChild',
+    'Event.target',
+    'MouseEvent.clientY',
+    'MouseEvent.clientX',
+
+    'Node.nodeType',
+    'Node.textContent',
+    
+    'HTMLCollection.length',
+    'HTMLCollection.item',
+    'Node.lastElementChild',
+    'Node.firstElementChild',
+    'HTMLElement_tabIndex',
+
+    'Element.clientWidth',
+    'Element.clientHeight',
+    'Document.body',
+    'Element.removeAttribute',
+    'Element.getBoundingClientRect',
+    'CSSStyleDeclaration.getPropertyValue',
+    'CSSStyleDeclaration.setProperty',
+    'CSSStyleDeclaration.__propertyQuery__',
+
+    # TODO(jacobr): consider implementing these methods as well as they show
+    # up in benchmarks for some sample applications.
+    #'Document.createEvent',
+    #'Document.initEvent',
+    #'EventTarget.dispatchEvent',
+     ])
+
+# Uncomment out this line  to short circuited native methods and run all of
+# dart:html through JS interop except for createElement which is slightly more
+# tightly natively wired.
+# _js_custom_members = Set([])
+
 HEADER = """/* Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
  * for details. All rights reserved. Use of this source code is governed by a
  * BSD-style license that can be found in the LICENSE file.
@@ -50,13 +126,14 @@ class Blink_Utils {
 
   static register(document, tag, customType, extendsTagName) native "Utils_register";
 
-  static createElement(document, tagName) native "Utils_createElement";
+  // Defines an interceptor if there is an appropriate JavaScript prototype to define it on.
-
+  // In any case, returns a typed JS wrapper compatibile with dart:html and the new
-  static constructElement(element_type, jsObject) native "Utils_constructor_create";
+  // typed JS Interop.
+  static defineInterceptorCustomElement(jsObject, Type type) native "Utils_defineInterceptorCustomElement";
+  static setInstanceInterceptor(o, Type type, {bool customElement: false}) native "Utils_setInstanceInterceptor";
 
+  // This method will throw if the element isn't actually a real Element.
   static initializeCustomElement(element) native "Utils_initializeCustomElement";
-
-  static changeElementWrapper(element, type) native "Utils_changeElementWrapper";
 }
 
 class Blink_DOMWindowCrossFrame {
@@ -106,9 +183,63 @@ class Blink_DOMStringMap {
 }
 
 // Calls through JsNative but returns DomException instead of error strings.
+class Stats {
+  Stats(this.name) {
+    counts = new Map<String, int>();
+  }
+
+  String name;
+  Map<String, int> counts;
+  clear() {
+    counts.clear();
+  }
+
+  track(String v) {
+    counts[v] = counts.putIfAbsent(v, ()=> 0) + 1;
+  }
+  toString() {
+    StringBuffer sb = new StringBuffer();
+    sb.write('================');
+    sb.write('$name ${counts.length}');
+    var keys = counts.keys.toList();
+    keys.sort((a,b) => counts[b].compareTo(counts[a]));
+    for (var key in keys) {
+      print("$key => ${counts[key]}");
+    }
+    sb.write('---------------');
+    sb.write('================');
+    return sb;
+  }
+}
+
+bool TRACK_STATS = true;
+dumpStats() {
+  print("------------ STATS ----------------");
+  print(Blink_JsNative_DomException.getPropertyStats.toString()); 
+  print(Blink_JsNative_DomException.setPropertyStats.toString());
+  print(Blink_JsNative_DomException.callMethodStats.toString());
+  print(Blink_JsNative_DomException.constructorStats.toString());
+  print("-----------------------------------");
+}
+
+clearStats() {
+  Blink_JsNative_DomException.getPropertyStats.clear();
+  Blink_JsNative_DomException.setPropertyStats.clear();
+  Blink_JsNative_DomException.callMethodStats.clear();  
+  Blink_JsNative_DomException.constructorStats.clear();  
+}
+
 class Blink_JsNative_DomException {
-  static getProperty(js.JsObject o, name) {
+  static var getPropertyStats = new Stats('get property');
+  static var setPropertyStats = new Stats('set property');
+  static var callMethodStats = new Stats('call method');
+  static var constructorStats = new Stats('constructor');
+
+  static var constructors = new Map<String, dynamic>();
+
+  static getProperty(o, String name) {
     try {
+      if (TRACK_STATS) getPropertyStats.track(name);
       return js.JsNative.getProperty(o, name);
     } catch (e) {
       // Re-throw any errors (returned as a string) as a DomException.
@@ -116,8 +247,51 @@ class Blink_JsNative_DomException {
     }
   }
 
-  static callMethod(js.JsObject o, String method, List args) {
+  static propertyQuery(o, String name) {
     try {
+      if (TRACK_STATS) getPropertyStats.track('__propertyQuery__');
+      return js.JsNative.getProperty(o, name);
+    } catch (e) {
+      // Re-throw any errors (returned as a string) as a DomException.
+      throw new DomException.jsInterop(e);
+    }
+  }
+
+  static callConstructor0(String name) {
+    try {
+      if (TRACK_STATS) constructorStats.track(name);
+      var constructor = constructors.putIfAbsent(name, () => js.context[name]);
+      return js.JsNative.callConstructor0(constructor);
+    } catch (e) {
+      // Re-throw any errors (returned as a string) as a DomException.
+      throw new DomException.jsInterop(e);
+    }
+  }
+
+  static callConstructor(String name, List args) {
+    try {
+      if (TRACK_STATS) constructorStats.track(name);
+      var constructor = constructors.putIfAbsent(name, () => js.context[name]);
+      return js.JsNative.callConstructor(constructor, args);
+    } catch (e) {
+      // Re-throw any errors (returned as a string) as a DomException.
+      throw new DomException.jsInterop(e);
+    }
+  }
+
+  static setProperty(o, String name, value) {
+    try {
+      if (TRACK_STATS) setPropertyStats.track(name);
+      return js.JsNative.setProperty(o, name, value);
+    } catch (e) {
+      // Re-throw any errors (returned as a string) as a DomException.
+      throw new DomException.jsInterop(e);
+    }
+  }
+
+  static callMethod(o, String method, List args) {
+    try {
+      if (TRACK_STATS) callMethodStats.track(method);
       return js.JsNative.callMethod(o, method, args);
     } catch (e) {
       // Re-throw any errors (returned as a string) as a DomException.
@@ -137,38 +311,73 @@ CLASS_DEFINITION_EXTENDS = """class Blink%s extends Blink%s {
 """
 
 #(interface_name)
-CONSTRUCTOR_0 = '  constructorCallback_0_() => new js.JsObject(Blink_JsNative_DomException.getProperty(js.context, "%s"), []);\n\n'
+
+#
+CONSTRUCTOR_0 = ['  constructorCallback_0_()',
+                 ' => Blink_JsNative_DomException.callConstructor0("%s");\n\n',
+                 ' native "Blink_Constructor_%s";\n\n']
 
 #(argument_count, arguments, interface_name, arguments)
-CONSTRUCTOR_ARGS = '  constructorCallback_%s_(%s) => new js.JsObject(Blink_JsNative_DomException.getProperty(js.context, "%s"), [%s]);\n\n'
+CONSTRUCTOR_ARGS = ['  constructorCallback_%s_(%s)',
+   ' => Blink_JsNative_DomException.callConstructor("%s", [%s]);\n\n',
+   ' native "Blink_Constructor_Args_%s" /* %s */;\n\n']
 
 #(attribute_name, attribute_name)
-ATTRIBUTE_GETTER = '  %s_Getter_(mthis) => Blink_JsNative_DomException.getProperty(mthis, "%s");\n\n'
+ATTRIBUTE_GETTER = ['  %s_Getter_(mthis)',
-ATTRIBUTE_SETTER = '  %s_Setter_(mthis, __arg_0) => mthis["%s"] = __arg_0;\n\n'
+                    ' => Blink_JsNative_DomException.getProperty(mthis /* %s */, "%s");\n\n',
+                    ' native "Blink_Getter_%s_%s";\n\n'
+                    ]
+
+ATTRIBUTE_SETTER = ['  %s_Setter_(mthis, __arg_0)',
+                    ' => Blink_JsNative_DomException.setProperty(mthis /* %s */, "%s", __arg_0);\n\n',
+                    ' native "Blink_Setter_%s_%s";\n\n'
+                    ]
 
 #(operation_name, operationName)
-OPERATION_0 = '  %s_Callback_0_(mthis) => Blink_JsNative_DomException.callMethod(mthis, "%s", []);\n\n'
+OPERATION_0 = ['  %s_Callback_0_(mthis)',
+               ' => Blink_JsNative_DomException.callMethod(mthis /* %s */, "%s", []);\n\n',
+               ' native "Blink_Operation_0_%s_%s";\n\n'
+               ]
 
 # getter, setter, deleter and propertyQuery code
-OPERATION_1 = '  $%s_Callback_1_(mthis, __arg_0) => Blink_JsNative_DomException.callMethod(mthis, "%s", [__arg_0]);\n\n'
+OPERATION_1 = ['  $%s_Callback_1_(mthis, __arg_0)',
-OPERATION_2 = '  $%s_Callback_2_(mthis, __arg_0, __arg_1) => Blink_JsNative_DomException.callMethod(mthis, "%s", [__arg_0, __arg_1]);\n\n'
+               ' => Blink_JsNative_DomException.callMethod(mthis /* %s */, "%s", [__arg_0]);\n\n',
-OPERATION_PQ = '  $%s_Callback_1_(mthis, __arg_0) => mthis[__arg_0];\n\n'
+               ' native "Blink_Operation_1_%s_%s";\n\n'
+               ]
+
+OPERATION_2 = ['  $%s_Callback_2_(mthis, __arg_0, __arg_1)',
+               ' => Blink_JsNative_DomException.callMethod(mthis /* %s */, "%s", [__arg_0, __arg_1]);\n\n',
+               ' native "Blink_Operation_2_%s_%s";\n\n']
+
+OPERATION_PQ = ['  $%s_Callback_1_(mthis, __arg_0)',
+                ' => Blink_JsNative_DomException.propertyQuery(mthis, __arg_0); /* %s */ \n\n',
+                ' native "Blink_Operation_PQ_%s";\n\n']
 
 #(operation_name, argument_count, arguments, operation_name, arguments)
 ARGUMENT_NUM = "__arg_%s"
-OPERATION_ARGS = '  %s_Callback_%s_(mthis, %s) => Blink_JsNative_DomException.callMethod(mthis, "%s", [%s]);\n\n'
+OPERATION_ARGS = ['  %s_Callback_%s_(mthis, %s)',
+                  ' => Blink_JsNative_DomException.callMethod(mthis /* %s */, "%s", [%s]);\n\n',
+                  ' native "Blink_Operation_%s_%s"; /* %s */\n\n']
+
+
 
 # get class property to make static call.
 CLASS_STATIC = 'Blink_JsNative_DomException.getProperty(js.context, "%s")'
 
 # name, classname_getproperty, name
-STATIC_ATTRIBUTE_GETTER = '  %s_Getter_() => Blink_JsNative_DomException.getProperty(%s, "%s");\n\n'
+STATIC_ATTRIBUTE_GETTER = ['  %s_Getter_()',
+                           ' => Blink_JsNative_DomException.getProperty(%s /* %s */, "%s");\n\n',
+                           ' /* %s */ native "Blink_Static_getter_%s_%s"']
 
 # name, classname_getproperty, name
-STATIC_OPERATION_0 = '  %s_Callback_0_() => Blink_JsNative_DomException.callMethod(%s, "%s", []);\n\n'
+STATIC_OPERATION_0 = ['  %s_Callback_0_()',
+                      ' => Blink_JsNative_DomException.callMethod(%s /* %s */, "%s", []);\n\n',
+                      ' /* %s */ native "Blink_Static_Operation_0_%s_%s']
 
 # name, argsCount, args, classname_getproperty, name, args
-STATIC_OPERATION_ARGS = '  %s_Callback_%s_(%s) => Blink_JsNative_DomException.callMethod(%s, "%s", [%s]);\n\n'
+STATIC_OPERATION_ARGS = ['  %s_Callback_%s_(%s)',
+                         ' => Blink_JsNative_DomException.callMethod(%s /* %s */, "%s", [%s]);\n\n',
+                         ' /* %s */ native "Blink_Static_Operations_%s_%s" /* %s */ \n\n']
 
 CLASS_DEFINITION_END = """}
 
@@ -197,6 +406,27 @@ constructor_renames = {
 def rename_constructor(name):
   return constructor_renames[name] if name in constructor_renames else name
 
+
+def _Find_Match(interface_id, member, member_prefix, candidates):
+  member_name = interface_id + '.' + member
+  if member_name in candidates:
+    return member_name
+  member_name = interface_id + '.' + member_prefix + member
+  if member_name in candidates:
+    return member_name
+  member_name = interface_id + '.*'
+  if member_name in candidates:
+    return member_name
+
+def _Is_Native(interface, member):
+  return _Find_Match(interface, member, '', _js_custom_members)
+
+def Select_Stub(template, is_native):
+  if is_native:
+    return template[0] + template[2]
+  else:
+    return template[0] + template[1]
+
 def Generate_Blink(output_dir, database, type_registry):
   blink_filename = os.path.join(output_dir, '_blink_dartium.dart')
   blink_file = open(blink_filename, 'w')
@@ -226,7 +456,7 @@ def Generate_Blink(output_dir, database, type_registry):
       _Emit_Blink_Constructors(blink_file, analyzed_constructors)
     elif 'Constructor' in interface.ext_attrs:
       # Zero parameter constructor.
-      blink_file.write(CONSTRUCTOR_0 % rename_constructor(name))
+      blink_file.write(Select_Stub(CONSTRUCTOR_0, _Is_Native(name, 'constructor')) % rename_constructor(name))
 
     _Process_Attributes(blink_file, interface, interface.attributes)
     _Process_Operations(blink_file, interface, interface.operations)
@@ -250,27 +480,29 @@ def _Emit_Blink_Constructors(blink_file, analyzed_constructors):
 
   for callback_index in range(arg_min_count, arg_max_count):
     if callback_index == 0:
-      blink_file.write(CONSTRUCTOR_0 % (rename_constructor(name)))
+      blink_file.write(Select_Stub(CONSTRUCTOR_0, _Is_Native(name, 'constructor')) % (rename_constructor(name)))
     else:
       arguments = []
       for i in range(0, callback_index):
         arguments.append(ARGUMENT_NUM % i)
       argument_list = ', '.join(arguments)
-      blink_file.write(CONSTRUCTOR_ARGS % (callback_index, argument_list, rename_constructor(name), argument_list))
+      blink_file.write(
+        Select_Stub(CONSTRUCTOR_ARGS, _Is_Native(name, 'constructor')) % (callback_index, argument_list, rename_constructor(name), argument_list))
 
 def _Process_Attributes(blink_file, interface, attributes):
   # Emit an interface's attributes and operations.
   for attribute in sorted(attributes, ConstantOutputOrder):
     name = attribute.id
+    is_native = _Is_Native(interface.id, name)
     if attribute.is_read_only:
       if attribute.is_static:
         class_property = CLASS_STATIC % interface.id
-        blink_file.write(STATIC_ATTRIBUTE_GETTER % (name, class_property, name))
+        blink_file.write(Select_Stub(STATIC_ATTRIBUTE_GETTER, is_native) % (name, class_property, interface.id, name))
       else:
-        blink_file.write(ATTRIBUTE_GETTER % (name, name))
+        blink_file.write(Select_Stub(ATTRIBUTE_GETTER, is_native) % (name, interface.id, name))
     else:
-      blink_file.write(ATTRIBUTE_GETTER % (name, name))
+      blink_file.write(Select_Stub(ATTRIBUTE_GETTER, is_native) % (name, interface.id, name))
-      blink_file.write(ATTRIBUTE_SETTER % (name, name))
+      blink_file.write(Select_Stub(ATTRIBUTE_SETTER, is_native) % (name, interface.id, name))
 
 def _Process_Operations(blink_file, interface, operations):
   analyzeOperations = []
@@ -292,6 +524,7 @@ def _Emit_Blink_Operation(blink_file, interface, analyzeOperations):
   analyzed = AnalyzeOperation(interface, analyzeOperations)
   (arg_min_count, arg_max_count) = generate_parameter_entries(analyzed.param_infos)
   name = analyzed.js_name
+  is_native = _Is_Native(interface.id, name)
 
   operation = analyzeOperations[0]
   if (name.startswith('__') and \
@@ -299,13 +532,13 @@ def _Emit_Blink_Operation(blink_file, interface, analyzeOperations):
        'setter' in operation.specials or \
        'deleter' in operation.specials)):
     if name == '__propertyQuery__':
-      blink_file.write(OPERATION_PQ % (name))
+      blink_file.write(Select_Stub(OPERATION_PQ, is_native) % (name, interface.id))
     else:
       arg_min_count = arg_max_count
       if arg_max_count == 2:
-        blink_file.write(OPERATION_1 % (name, name))
+        blink_file.write(Select_Stub(OPERATION_1, is_native) % (name, interface.id, name))
       elif arg_max_count == 3:
-        blink_file.write(OPERATION_2 % (name, name))
+        blink_file.write(Select_Stub(OPERATION_2, is_native) % (name, interface.id, name))
       else:
         print "FATAL ERROR: _blink emitter operator %s.%s" % (interface.id, name)
         exit
@@ -316,9 +549,9 @@ def _Emit_Blink_Operation(blink_file, interface, analyzeOperations):
     if callback_index == 0:
       if operation.is_static:
         class_property = CLASS_STATIC % interface.id
-        blink_file.write(STATIC_OPERATION_0 % (name, class_property, name))
+        blink_file.write(Select_Stub(STATIC_OPERATION_0, is_native) % (name, class_property, interface.id, name))
       else:
-        blink_file.write(OPERATION_0 % (name, name))
+        blink_file.write(Select_Stub(OPERATION_0, is_native) % (name, interface.id, name))
     else:
       arguments = []
       for i in range(0, callback_index):
@@ -326,6 +559,6 @@ def _Emit_Blink_Operation(blink_file, interface, analyzeOperations):
       argument_list = ', '.join(arguments)
       if operation.is_static:
         class_property = CLASS_STATIC % interface.id
-        blink_file.write(STATIC_OPERATION_ARGS % (name, callback_index, argument_list, class_property, name, argument_list))
+        blink_file.write(Select_Stub(STATIC_OPERATION_ARGS, is_native) % (name, callback_index, argument_list, class_property, interface.id, name, argument_list))
       else:
-        blink_file.write(OPERATION_ARGS % (name, callback_index, argument_list, name, argument_list))
+        blink_file.write(Select_Stub(OPERATION_ARGS, is_native) % (name, callback_index, argument_list, interface.id, name, argument_list))

tools/dom/scripts/generator.py

@@ -543,29 +543,28 @@ class OperationInfo(object):
         type_id = p.type_id
         # Unwrap the type to get the JsObject if Type is:
         #
-        #    - known IDL type
         #    - type_id is None then it's probably a union type or overloaded
         #      it's a dynamic/any type
         #    - type is Object
         #
-        # JsObject maybe stored in the Dart class.
         if (wrap_unwrap_type_blink(type_id, type_registry)):
           type_is_callback = self.isCallback(type_registry, type_id)
           if (dart_js_interop and type_id == 'EventListener' and
               self.name in ['addEventListener', 'removeEventListener']):
-              # Events fired need use a JsFunction not a anonymous closure to
+              # Events fired need use a JSFunction not a anonymous closure to
               # insure the event can really be removed.
-              parameters.append('unwrap_jso(js.allowInterop(%s))' % p.name)
+              parameters.append('js.allowInterop(%s)' % p.name)
-          elif dart_js_interop and type_id == 'FontFaceSetForEachCallback':
+# These commented out cases don't actually generate any code.              
+#          elif dart_js_interop and type_id == 'FontFaceSetForEachCallback':
               # forEach is supported in the DOM for FontFaceSet as it iterates
               # over the Javascript Object the callback parameters are also
               # Javascript objects and must be wrapped.
-              parameters.append('unwrap_jso((fontFace, fontFaceAgain, set) => %s(wrap_jso(fontFace), wrap_jso(fontFaceAgain), wrap_jso(set)))' % p.name)
+ #             parameters.append('(fontFace, fontFaceAgain, set) => %s(fontFace, fontFaceAgain, wrap_jso(set))' % p.name)
-          elif dart_js_interop and type_id == 'HeadersForEachCallback':
+#          elif dart_js_interop and type_id == 'HeadersForEachCallback':
               # forEach is supported in the DOM for Headers as it iterates
               # over the Javascript Object the callback parameters are also
               # Javascript objects and must be wrapped.
-              parameters.append('unwrap_jso((String value, String key, map) => %s(value, key, wrap_jso(map)))' % p.name)
+#              parameters.append('(String value, String key, map) => %s(value, key, wrap_jso(map))' % p.name)
           elif dart_js_interop and type_is_callback and not(isRemoveOperation):
             # Any remove operation that has a a callback doesn't need wrapping.
             # TODO(terry): Kind of hacky but handles all the cases we care about
@@ -579,15 +578,15 @@ class OperationInfo(object):
                 dart_type = type_registry.DartType(callback_arg.type.id) + ' '
               callback_args_decl.append('%s%s' % (dart_type, callback_arg.id))
               if wrap_unwrap_type_blink(callback_arg.type.id, type_registry):
-                callback_args_call.append('wrap_jso(%s)' % callback_arg.id)
+                callback_args_call.append(callback_arg.id)
               else:
                 callback_args_call.append(callback_arg.id)
-            parameters.append('unwrap_jso((%s) => %s(%s))' %
+            parameters.append('(%s) => %s(%s)' %
                               (", ".join(callback_args_decl),
-                               p.name,
+                              p.name,
-                               ", ".join(callback_args_call)))
+                              ", ".join(callback_args_call)))
           else:
-            parameters.append('unwrap_jso(%s)' % p.name)
+            parameters.append(p.name)
         else:
           if dart_js_interop:
             conversion = backend._InputConversion(p.type_id, self.declared_name)
@@ -1495,6 +1494,8 @@ def get_list_type(return_type):
   # Get the list type NNNN inside of List<NNNN>
   return return_type[5:-1] if isList(return_type) else return_type
 
+# TODO(jacobr): remove these obsolete methods as we don't actually
+# perform any wrapping.
 def wrap_unwrap_list_blink(return_type, type_registry):
   """Return True if the type is the list type is a blink know
      type e.g., List<Node>, List<FontFace>, etc."""
@@ -1508,14 +1509,9 @@ def wrap_unwrap_type_blink(return_type, type_registry):
     unwrap_jso"""
     if return_type and return_type.startswith('Html'):
         return_type = return_type.replace('Html', 'HTML', 1)
-    return (type_registry.HasInterface(return_type) or not(return_type) or
+    return (not(return_type) or
             return_type == 'Object' or
-            return_type == 'dynamic' or
+            return_type == 'dynamic')
-            return_type == 'Future' or
-            return_type == 'SqlDatabase' or # renamed to Database
-            return_type == 'HTMLElement' or
-            return_type == 'MutationObserver' or
-            (return_type.endswith('[]') and return_type != 'DOMString[]'))
 
 def wrap_type_blink(return_type, type_registry):
     """Returns True if the type is a blink type that requires wrap_jso but

tools/dom/scripts/htmldartgenerator.py

@@ -626,7 +626,7 @@ class HtmlDartGenerator(object):
             (factory_params, converted_arguments) = self._ConvertArgumentTypes(
                 stmts_emitter, arguments, argument_count, constructor_info)
             args = ', '.join(converted_arguments)
-            call_template = 'wrap_jso($FACTORY_NAME($FACTORY_PARAMS))'
+            call_template = '$FACTORY_NAME($FACTORY_PARAMS)'
         else:
             qualified_name = emitter.Format(
                 '$FACTORY.$NAME',

tools/dom/scripts/systemhtml.py

@@ -586,7 +586,7 @@ class HtmlDartInterfaceGenerator(object):
         class_modifiers = ''
       else:
         # For Dartium w/ JsInterop these suppressed interfaces are needed to
-        # instanciate the internal classes when wrap_jso is called for a JS object.
+        # instanciate the internal classes.
         if (self._renamer.ShouldSuppressInterface(self._interface) and
             not(isinstance(self._backend, Dart2JSBackend)) and
             self._options.dart_js_interop):
@@ -600,21 +600,10 @@ class HtmlDartInterfaceGenerator(object):
 
     class_name = self._interface_type_info.implementation_name()
 
-    js_interop_equivalence_op = \
-      '  bool operator ==(other) => unwrap_jso(other) == unwrap_jso(this) || identical(this, other);\n' \
-      + '  int get hashCode => unwrap_jso(this).hashCode;\n'
-    # ClientRect overrides the equivalence operator.
-    if interface_name == 'ClientRect' or interface_name == 'DomRectReadOnly':
-        js_interop_equivalence_op = ''
-
     js_interop_wrapper = '''
 
   @Deprecated("Internal Use Only")
-  static {0} internalCreate{0}() {{
+  external static Type get instanceRuntimeType;
-    return new {0}._internalWrap();
-  }}
-
-  external factory {0}._internalWrap();
 
   @Deprecated("Internal Use Only")
   {0}.internal_() : super.internal_();
@@ -622,19 +611,13 @@ class HtmlDartInterfaceGenerator(object):
 '''.format(class_name)
     if base_class == 'NativeFieldWrapperClass2' or base_class == 'DartHtmlDomObject':
         js_interop_wrapper = '''
-  @Deprecated("Internal Use Only")
-  static {0} internalCreate{0}() {{
-    return new {0}._internalWrap();
-  }}
 
-  factory {0}._internalWrap() {{
+  @Deprecated("Internal Use Only")
-    return new {0}.internal_();
+  external static Type get instanceRuntimeType;
-  }}
 
   @Deprecated("Internal Use Only")
   {0}.internal_() {{ }}
-
+'''.format(class_name)
-{1}'''.format(class_name, js_interop_equivalence_op)
         # Change to use the synthesized class so we can construct with a mixin
         # classes prefixed with name of NativeFieldWrapperClass2 don't have a
         # default constructor so classes with mixins can't be new'd.
@@ -1285,13 +1268,9 @@ class DartLibrary():
     emitters = library_emitter.Emit(
         self._template, AUXILIARY_DIR=massage_path(auxiliary_dir))
     if isinstance(emitters, tuple):
-      if self._dart_js_interop:
+      imports_emitter, map_emitter = emitters
-        imports_emitter, map_emitter, function_emitter = emitters
-      else:
-        imports_emitter, map_emitter = emitters
-        function_emitter = None
     else:
-      imports_emitter, map_emitter, function_emitter = emitters, None, None
+      imports_emitter, map_emitter = emitters, None
 
     for path in sorted(self._paths):
       relpath = os.path.relpath(path, library_file_dir)
@@ -1304,26 +1283,10 @@ class DartLibrary():
       items.sort()
       for (idl_name, dart_name) in items:
         map_emitter.Emit(
-          "  '$IDL_NAME': () => $DART_NAME,\n",
+          "  '$IDL_NAME': () => $DART_NAME.instanceRuntimeType,\n",
           IDL_NAME=idl_name,
           DART_NAME=dart_name)
 
-    # Emit the $!TYPE_FUNCTION_MAP
-    if function_emitter:
-      items = self._typeMap.items()
-      items.sort()
-      for (idl_name, dart_name) in items:
-        # DOMStringMap is in the abstract list but is used as a concrete class
-        # in Dartium.
-        if not IsPureInterface(idl_name):
-          # Handle classes that are concrete (abstract can't be instantiated).
-          function_emitter.Emit(
-            "  '$IDL_NAME': () => $DART_NAME.internalCreate$DART_NAME,\n",
-            IDL_NAME=idl_name,
-            DART_NAME=dart_name)
-      if self._dart_path.endswith('html_dartium.dart'):
-        function_emitter.Emit("  'polymer-element': () => HtmlElement.internalCreateHtmlElement,\n")
-
 
 # ------------------------------------------------------------------------------
 

tools/dom/scripts/systemnative.py

@@ -22,6 +22,8 @@ _url_utils = ['hash', 'host', 'hostname', 'origin',
               'password', 'pathname', 'port', 'protocol',
               'search', 'username']
 
+_promise_to_future = Conversion('convertNativePromiseToDartFuture', 'dynamic', 'Future')
+
 def array_type(data_type):
     matched = re.match(r'([\w\d_\s]+)\[\]', data_type)
     if not matched:
@@ -108,6 +110,16 @@ class DartiumBackend(HtmlDartGenerator):
   def CustomJSMembers(self):
     return {}
 
+  def _OutputConversion(self, idl_type, member):
+    conversion = FindConversion(idl_type, 'get', self._interface.id, member)
+    # TODO(jacobr) handle promise consistently in dart2js and dartium.
+    if idl_type == 'Promise':
+      return _promise_to_future
+    if conversion:
+      if conversion.function_name in ('_convertNativeToDart_Window', '_convertNativeToDart_EventTarget', 'convertNativeToDart_DateTime', 'convertNativeToDart_ImageData'):
+        return None
+    return conversion
+
   def _InputConversion(self, idl_type, member):
     return FindConversion(idl_type, 'set', self._interface.id, member)
 
@@ -250,7 +262,7 @@ class DartiumBackend(HtmlDartGenerator):
         self._members_emitter.Emit(
             '\n  @DocsEditable()\n'
             '  static $INTERFACE_NAME $FACTORY_METHOD_NAME($PARAMETERS) => '
-            'wrap_jso($TOPLEVEL_NAME($OUTPARAMETERS));\n',
+            '$TOPLEVEL_NAME($OUTPARAMETERS);\n',
             INTERFACE_NAME=self._interface_type_info.interface_name(),
             FACTORY_METHOD_NAME=factory_method_name,
             PARAMETERS=typed_formals,
@@ -272,7 +284,7 @@ class DartiumBackend(HtmlDartGenerator):
         self._interface, self._interface.id, '  ')
 
     self._members_emitter.Emit(
-        '\n  $(ANNOTATIONS)factory $CTOR($PARAMS) => wrap_jso(_create($FACTORY_PARAMS));\n',
+        '\n  $(ANNOTATIONS)factory $CTOR($PARAMS) => _create($FACTORY_PARAMS);\n',
         ANNOTATIONS=annotations,
         CTOR=constructor_info._ConstructorFullName(self._DartType),
         PARAMS=constructor_info.ParametersAsDeclaration(self._DartType),
@@ -536,7 +548,7 @@ class DartiumBackend(HtmlDartGenerator):
         # JsObject maybe stored in the Dart class.
         return_wrap_jso = wrap_return_type_blink(return_type, attr.type.id, self._type_registry)
     wrap_unwrap_list.append(return_wrap_jso)       # wrap_jso the returned object
-    wrap_unwrap_list.append(self._dart_use_blink)  # this must be unwrap_jso
+    wrap_unwrap_list.append(self._dart_use_blink) 
 
     # This seems to have been replaced with Custom=Getter (see above), but
     # check to be sure we don't see the old syntax
@@ -545,10 +557,13 @@ class DartiumBackend(HtmlDartGenerator):
     auto_scope_setup = self._GenerateAutoSetupScope(attr.id, native_suffix)
     native_entry = \
         self.DeriveNativeEntry(attr.id, 'Getter', None)
+    output_conversion = self._OutputConversion(attr.type.id, attr.id)
+
     cpp_callback_name = self._GenerateNativeBinding(attr.id, 1,
         dart_declaration, attr.is_static, return_type, parameters,
         native_suffix, is_custom, auto_scope_setup, native_entry=native_entry,
-        wrap_unwrap_list=wrap_unwrap_list, dictionary_return=dictionary_returned)
+        wrap_unwrap_list=wrap_unwrap_list, dictionary_return=dictionary_returned,
+        output_conversion=output_conversion)
     if is_custom:
       return
 
@@ -583,9 +598,7 @@ class DartiumBackend(HtmlDartGenerator):
 
     # Is the setter value a DartClass (that has a JsObject) or the type is
     # None (it's a dynamic/any type) then unwrap_jso before passing to blink.
-    parameters = ['unwrap_jso(value)' if (isinstance(type_info, InterfaceIDLTypeInfo) or
+    parameters = ['value']
-                                          not(attr.type.id) or ptype == 'Object')
-                  else 'value']
 
     dart_declaration = 'set %s(%s value)' % (html_name, ptype)
     is_custom = _IsCustom(attr) and (_IsCustomValue(attr, None) or
@@ -651,6 +664,12 @@ class DartiumBackend(HtmlDartGenerator):
       self._EmitExplicitIndexedGetter(dart_element_type)
     else:
       is_custom = any((op.id == 'item' and _IsCustom(op)) for op in self._interface.operations)
+
+      output_conversion = self._OutputConversion(element_type, 'item')
+      conversion_name = ''
+      if output_conversion:
+        conversion_name = output_conversion.function_name
+
       # First emit a toplevel function to do the native call
       # Calls to this are emitted elsewhere,
       dart_native_name, resolver_string = \
@@ -663,40 +682,22 @@ class DartiumBackend(HtmlDartGenerator):
                                         dart_native_name)
 
       type_info = self._TypeInfo(element_type)
-      # Does nativeIndexGetter return a DartClass (JsObject) if so wrap_jso.
-      wrap_jso_start = ''
-      wrap_jso_end = ''
-      if (isinstance(type_info, InterfaceIDLTypeInfo) or
-          wrap_type_blink(type_info.narrow_dart_type(), self._type_registry)):
-          wrap_jso_start = 'wrap_jso('
-          wrap_jso_end = ')'
       blinkNativeIndexed = """
   $TYPE operator[](int index) {
     if (index < 0 || index >= length)
       throw new RangeError.index(index, this);
-    return %s$(DART_NATIVE_NAME)(unwrap_jso(this), index)%s;
+    return _nativeIndexedGetter(index);
   }
 
-  $TYPE _nativeIndexedGetter(int index) => %s$(DART_NATIVE_NAME)(unwrap_jso(this), index)%s;
+  $TYPE _nativeIndexedGetter(int index) => $(CONVERSION_NAME)($(DART_NATIVE_NAME)(this, index));
-""" % (wrap_jso_start, wrap_jso_end, wrap_jso_start, wrap_jso_end)
+"""
-      # Wrap the type to store the JsObject if Type is:
+      blinkNativeIndexedGetter = \
-      #
+          ' $(DART_NATIVE_NAME)(this, index);\n'
-      #    - known IDL type
-      #    - type_id is None then it's probably a union type or overloaded
-      #      it's a dynamic/any type
-      #    - type is Object
-      #
-      # JsObject maybe stored in the Dart class.
-      if isinstance(type_info, InterfaceIDLTypeInfo) or not(type_info) or dart_element_type == 'Object':
-          blinkNativeIndexedGetter = \
-              ' {0}$(DART_NATIVE_NAME)(unwrap_jso(this), index){1};\n'.format('wrap_jso(', ')')
-      else:
-          blinkNativeIndexedGetter = \
-              ' $(DART_NATIVE_NAME)(unwrap_jso(this), index);\n'
       self._members_emitter.Emit(blinkNativeIndexed,
                                  DART_NATIVE_NAME=dart_qualified_name,
                                  TYPE=self.SecureOutputType(element_type),
-                                 INTERFACE=self._interface.id)
+                                 INTERFACE=self._interface.id,
+                                 CONVERSION_NAME=conversion_name)
 
     if self._HasNativeIndexSetter():
       self._EmitNativeIndexSetter(dart_element_type)
@@ -798,6 +799,8 @@ class DartiumBackend(HtmlDartGenerator):
 
     operation = info.operations[0]
 
+    output_conversion = self._OutputConversion(operation.type.id, operation.id)
+
     dictionary_returned = False
     # Return type for dictionary is any (untyped).
     if operation.type.id == 'Dictionary':
@@ -821,20 +824,14 @@ class DartiumBackend(HtmlDartGenerator):
     if self._dart_use_blink:
         # Wrap the type to store the JsObject if Type is:
         #
-        #    - known IDL type
-        #    - type_id is None then it's probably a union type or overloaded
         #      it's a dynamic/any type
         #    - type is Object
         #
         # JsObject maybe stored in the Dart class.
         return_wrap_jso = wrap_return_type_blink(return_type, info.type_name, self._type_registry)
         return_type_info = self._type_registry.TypeInfo(info.type_name)
-        if (isinstance(return_type_info, SequenceIDLTypeInfo) and
-            not isinstance(return_type_info._item_info, PrimitiveIDLTypeInfo)):
-                return_wrap_jso = True
     # wrap_jso the returned object
     wrap_unwrap_list.append(return_wrap_jso)
-    # The 'this' parameter must be unwrap_jso
     wrap_unwrap_list.append(self._dart_use_blink)
 
     if info.callback_args:
@@ -852,7 +849,8 @@ class DartiumBackend(HtmlDartGenerator):
         native_suffix, is_custom, auto_scope_setup,
         native_entry=native_entry,
         wrap_unwrap_list=wrap_unwrap_list,
-        dictionary_return=dictionary_returned)
+        dictionary_return=dictionary_returned,
+        output_conversion=output_conversion)
       if not is_custom:
         self._GenerateOperationNativeCallback(operation, operation.arguments, cpp_callback_name, auto_scope_setup)
     else:
@@ -880,7 +878,7 @@ class DartiumBackend(HtmlDartGenerator):
       base_name = '_%s_%s' % (operation.id, version)
       static = True
       if not operation.is_static:
-        actuals = ['unwrap_jso(this)' if self._dart_use_blink else 'this'] + actuals
+        actuals = ['this'] + actuals
         formals = ['mthis'] + formals
       actuals_s = ", ".join(actuals)
       formals_s = ", ".join(formals)
@@ -892,10 +890,7 @@ class DartiumBackend(HtmlDartGenerator):
       overload_name = \
           self.DeriveQualifiedBlinkName(self._interface.id,
                                         overload_base_name)
-      if return_wrap_jso:
+      call_emitter.Emit('$NAME($ARGS)', NAME=overload_name, ARGS=actuals_s)
-          call_emitter.Emit('wrap_jso($NAME($ARGS))', NAME=overload_name, ARGS=actuals_s)
-      else:
-          call_emitter.Emit('$NAME($ARGS)', NAME=overload_name, ARGS=actuals_s)
       auto_scope_setup = \
         self._GenerateAutoSetupScope(base_name, native_suffix)
       cpp_callback_name = self._GenerateNativeBinding(
@@ -927,7 +922,7 @@ class DartiumBackend(HtmlDartGenerator):
   def _GenerateNativeBinding(self, idl_name, argument_count, dart_declaration,
       static, return_type, parameters, native_suffix, is_custom,
       auto_scope_setup=True, emit_metadata=True, emit_to_native=False,
-      native_entry=None, wrap_unwrap_list=[], dictionary_return=False):
+      native_entry=None, wrap_unwrap_list=[], dictionary_return=False, output_conversion=None):
     metadata = []
     if emit_metadata:
       metadata = self._metadata.GetFormattedMetadata(
@@ -946,10 +941,7 @@ class DartiumBackend(HtmlDartGenerator):
 
     if not static:
         formals = ", ".join(['mthis'] + parameters)
-        if wrap_unwrap_list and wrap_unwrap_list[1]:
+        actuals = ", ".join(['this'] + parameters)
-            actuals = ", ".join(['unwrap_jso(this)'] + parameters)
-        else:
-            actuals = ", ".join(['this'] + parameters)
     else:
         formals = ", ".join(parameters)
         actuals = ", ".join(parameters)
@@ -969,11 +961,17 @@ class DartiumBackend(HtmlDartGenerator):
             emit_template = '''
   $METADATA$DART_DECLARATION => $DART_NAME($ACTUALS);
   '''
-            if wrap_unwrap_list and wrap_unwrap_list[0]:
+            if output_conversion and not dictionary_return:
+              conversion_template = '''
+  $METADATA$DART_DECLARATION => %s($DART_NAME($ACTUALS));
+  '''
+              emit_template = conversion_template % output_conversion.function_name
+
+            elif wrap_unwrap_list and wrap_unwrap_list[0]:
                 if return_type == 'Rectangle':
                     jso_util_method = 'make_dart_rectangle'
                 elif wrap_unwrap_list[0]:
-                    jso_util_method = 'wrap_jso'
+                    jso_util_method = ''
 
                 if dictionary_return:
                   emit_jso_template = '''

tools/dom/src/dartium_CustomElementSupport.dart

@@ -29,40 +29,11 @@ class _VMElementUpgrader implements ElementUpgrader {
   }
 
   Element upgrade(element) {
-    var jsObject;
+    // Only exact type matches are supported- cannot be a subclass.
-    var tag;
+    if (element.runtimeType != _nativeType) {
-    var isNativeElementExtension = false;
+      throw new ArgumentError('element is not subclass of $_nativeType');
-
-    try {
-      tag = _getCustomElementName(element);
-    } catch (e) {
-      isNativeElementExtension = element.localName == _extendsTag;
     }
-
+    return _createCustomUpgrader(_type, element);
-    if (element.runtimeType == HtmlElement || element.runtimeType == TemplateElement) {
-      if (tag != _extendsTag) {
-        throw new UnsupportedError('$tag is not registered.');
-      }
-      jsObject = unwrap_jso(element);
-    } else if (element.runtimeType == js.JsObject) {
-      // It's a Polymer core element (written in JS).
-      jsObject = element;
-    } else if (isNativeElementExtension) {
-      // Extending a native element.
-      jsObject = element.blink_jsObject;
-
-      // Element to extend is the real tag.
-      tag = element.localName;
-    } else if (tag != null && element.localName != tag) {
-      throw new UnsupportedError('Element is incorrect type. Got ${element.runtimeType}, expected native Html or Svg element to extend.');
-    } else if (tag == null) {
-      throw new UnsupportedError('Element is incorrect type. Got ${element.runtimeType}, expected HtmlElement/JsObject.');
-    }
-
-    // Remember Dart class to tagName for any upgrading done in wrap_jso.
-    addCustomElementType(tag, _type, _extendsTag);
-
-    return _createCustomUpgrader(_type, jsObject);
   }
 }
 

tools/dom/src/dartium_KeyEvent.dart

@@ -30,13 +30,7 @@ part of html;
 @Experimental()
 class KeyEvent extends _WrappedEvent implements KeyboardEvent {
   /** Needed because KeyboardEvent is implements.
-   *  TODO(terry): Consider making blink_jsObject private (add underscore) for
-   *               all blink_jsObject.  Then needed private wrap/unwrap_jso
-   *               functions that delegate to a public wrap/unwrap_jso.
    */
-  @Deprecated("Internal Use Only")
-  js.JsObject blink_jsObject;
-
   /** The parent KeyboardEvent that this KeyEvent is wrapping and "fixing". */
   KeyboardEvent _parent;
 

tools/dom/src/dartium_WrappedEvent.dart

@@ -6,15 +6,14 @@ part of dart.html;
 
 /**
  * Helper class to implement custom events which wrap DOM events.
+ * TODO(jacobr): consider using dart JsNative.$setInstanceInterceptor
+ * instead of using wrappers as that would allow passing these wrappers
+ * back through dispatchEvent unlike the current implementation.
+ * See https://github.com/dart-lang/sdk/issues/16869
  */
 class _WrappedEvent implements Event {
   /** Needed because KeyboardEvent is implements.
-   *  TODO(terry): Consider making blink_jsObject private (add underscore) for
-   *               all blink_jsObject.  Then needed private wrap/unwrap_jso
-   *               functions that delegate to a public wrap/unwrap_jso.
    */
-  js.JsObject blink_jsObject;
-
   final Event wrapped;
 
   /** The CSS selector involved with event delegation. */

tools/dom/src/native_DOMImplementation.dart

@@ -124,8 +124,6 @@ class _Utils {
     }
   }
 
-  static maybeUnwrapJso(obj) => unwrap_jso(obj);
-
   static List convertToList(List list) {
     // FIXME: [possible optimization]: do not copy the array if Dart_IsArray is fine w/ it.
     final length = list.length;
@@ -189,15 +187,14 @@ class _Utils {
     return element;
   }
 
-  static window() => wrap_jso(js.context['window']);
-
   static forwardingPrint(String message) => _blink.Blink_Utils.forwardingPrint(message);
   static void spawnDomHelper(Function f, int replyTo) =>
       _blink.Blink_Utils.spawnDomHelper(f, replyTo);
 
   // TODO(vsm): Make this API compatible with spawnUri.  It should also
   // return a Future<Isolate>.
-  static spawnDomUri(String uri) => wrap_jso(_blink.Blink_Utils.spawnDomUri(uri));
+  // TODO(jacobr): IS THIS RIGHT? I worry we have broken conversion from Promise to Future.
+  static spawnDomUri(String uri) => _blink.Blink_Utils.spawnDomUri(uri);
 
   // The following methods were added for debugger integration to make working
   // with the Dart C mirrors API simpler.
@@ -774,13 +771,13 @@ class _Utils {
     return [
         "inspect",
         (o) {
-          host.callMethod("_inspect", [unwrap_jso(o)]);
+          js.JsNative.callMethod(host, "_inspect", [o]);
           return o;
         },
         "dir",
-        window().console.dir,
+        window.console.dir,
         "dirxml",
-        window().console.dirxml
+        window.console.dirxml
         // FIXME: add copy method.
         ];
   }
@@ -804,38 +801,34 @@ class _Utils {
   }
 
   static void _register(Document document, String tag, Type customType,
-    String extendsTagName) => _blink.Blink_Utils.register(unwrap_jso(document), tag, customType, extendsTagName);
+    String extendsTagName) => _blink.Blink_Utils.register(document, tag, customType, extendsTagName);
 
   static Element createElement(Document document, String tagName) =>
-      wrap_jso(_blink.Blink_Utils.createElement(unwrap_jso(document), tagName));
+      _blink.Blink_Utils.createElement(document, tagName);
-
-  static Element changeElementWrapper(HtmlElement element, Type type) =>
-      wrap_jso(_blink.Blink_Utils.changeElementWrapper(unwrap_jso(element), type));
 }
 
+// TODO(jacobr): this seems busted. I believe we are actually
+// giving users real windows for opener, parent, top, etc.
+// Or worse, we are probaly returning a raw JSObject.
 class _DOMWindowCrossFrame extends DartHtmlDomObject implements
     WindowBase {
-  /** Needed because KeyboardEvent is implements.
-   *  TODO(terry): Consider making blink_jsObject private (add underscore) for
-   *               all blink_jsObject.  Then needed private wrap/unwrap_jso
-   *               functions that delegate to a public wrap/unwrap_jso.
-   */
-  js.JsObject blink_jsObject;
 
   _DOMWindowCrossFrame.internal();
+  
+  static _createSafe(win) => _blink.Blink_Utils.setInstanceInterceptor(win, _DOMWindowCrossFrame);
 
   // Fields.
-  HistoryBase get history => wrap_jso(_blink.Blink_DOMWindowCrossFrame.get_history(unwrap_jso(this)));
+  HistoryBase get history => _blink.Blink_DOMWindowCrossFrame.get_history(this);
-  LocationBase get location => wrap_jso(_blink.Blink_DOMWindowCrossFrame.get_location(unwrap_jso(this)));
+  LocationBase get location => _blink.Blink_DOMWindowCrossFrame.get_location(this);
-  bool get closed => wrap_jso(_blink.Blink_DOMWindowCrossFrame.get_closed(unwrap_jso(this)));
+  bool get closed => _blink.Blink_DOMWindowCrossFrame.get_closed(this);
-  WindowBase get opener => wrap_jso(_blink.Blink_DOMWindowCrossFrame.get_opener(unwrap_jso(this)));
+  WindowBase get opener => _blink.Blink_DOMWindowCrossFrame.get_opener(this);
-  WindowBase get parent => wrap_jso(_blink.Blink_DOMWindowCrossFrame.get_parent(unwrap_jso(this)));
+  WindowBase get parent => _blink.Blink_DOMWindowCrossFrame.get_parent(this);
-  WindowBase get top => wrap_jso(_blink.Blink_DOMWindowCrossFrame.get_top(unwrap_jso(this)));
+  WindowBase get top => _blink.Blink_DOMWindowCrossFrame.get_top(this);
 
   // Methods.
-  void close() => _blink.Blink_DOMWindowCrossFrame.close(unwrap_jso(this));
+  void close() => _blink.Blink_DOMWindowCrossFrame.close(this);
   void postMessage(/*SerializedScriptValue*/ message, String targetOrigin, [List messagePorts]) =>
-      _blink.Blink_DOMWindowCrossFrame.postMessage(unwrap_jso(this),
+      _blink.Blink_DOMWindowCrossFrame.postMessage(this,
          convertDartToNative_SerializedScriptValue(message), targetOrigin, messagePorts);
 
   // Implementation support.
@@ -869,9 +862,9 @@ class _HistoryCrossFrame extends DartHtmlDomObject implements HistoryBase {
   _HistoryCrossFrame.internal();
 
   // Methods.
-  void back() => _blink.Blink_HistoryCrossFrame.back(unwrap_jso(this));
+  void back() => _blink.Blink_HistoryCrossFrame.back(this);
-  void forward() => _blink.Blink_HistoryCrossFrame.forward(unwrap_jso(this));
+  void forward() => _blink.Blink_HistoryCrossFrame.forward(this);
-  void go(int distance) => _blink.Blink_HistoryCrossFrame.go(unwrap_jso(this), distance);
+  void go(int distance) => _blink.Blink_HistoryCrossFrame.go(this, distance);
 
   // Implementation support.
   String get typeName => "History";
@@ -881,7 +874,7 @@ class _LocationCrossFrame extends DartHtmlDomObject implements LocationBase {
   _LocationCrossFrame.internal();
 
   // Fields.
-  set href(String h) => _blink.Blink_LocationCrossFrame.set_href(unwrap_jso(this), h);
+  set href(String h) => _blink.Blink_LocationCrossFrame.set_href(this, h);
 
   // Implementation support.
   String get typeName => "Location";

tools/dom/templates/html/dart2js/html_dart2js.darttemplate

@@ -150,7 +150,4 @@ Future<Isolate> spawnDomUri(Uri uri, List<String> args, message) {
   throw new UnimplementedError();
 }
 
-/// Dartium functions that are a NOOP in dart2js.
-unwrap_jso(dartClass_instance) => dartClass_instance;
-wrap_jso(jsObject) => jsObject;
 createCustomUpgrader(Type customElementClass, $this) => $this;

tools/dom/templates/html/dartium/html_dartium.darttemplate

@@ -37,7 +37,6 @@ import 'dart:_internal' hide Symbol;
 import 'dart:html_common';
 import 'dart:indexed_db';
 import 'dart:indexed_db' show indexed_dbBlinkMap;
-import 'dart:indexed_db' show indexed_dbBlinkFunctionMap;
 import 'dart:isolate';
 import 'dart:js' as js;
 import "dart:convert";
@@ -49,17 +48,14 @@ import 'dart:nativewrappers';
 import 'dart:typed_data';
 import 'dart:web_gl' as gl;
 import 'dart:web_gl' show web_glBlinkMap;
-import 'dart:web_gl' show web_glBlinkFunctionMap;
 import 'dart:web_sql';
 // Not actually used, but imported since dart:html can generate these objects.
 import 'dart:svg' as svg;
 import 'dart:svg' show svgBlinkMap;
-import 'dart:svg' show svgBlinkFunctionMap;
 import 'dart:svg' show Matrix;
 import 'dart:svg' show SvgSvgElement;
 import 'dart:web_audio' as web_audio;
 import 'dart:web_audio' show web_audioBlinkMap;
-import 'dart:web_audio' show web_audioBlinkFunctionMap;
 import 'dart:_blink' as _blink;
 import 'dart:developer';
 
@@ -118,7 +114,7 @@ Window get window {
   }
 $if DARTIUM
 $if JSINTEROP
-  _window = wrap_jso(js.JsNative.getProperty(js.context, 'window'));
+  _window = js.JsNative.toTypedObject(js.context);
 $else
   _window = _Utils.window();
 $endif
@@ -161,11 +157,19 @@ final htmlBlinkMap = {
   'JsObject': () => js.JsObject,
   'JsFunction': () => js.JsFunction,
   'JsArray': () => js.JsArray,
+  // We have to call .instanceRuntimeType as these classes have a private
+  // implementation class defined dynamically at runtime via a patch file.
+  'JSObject': () => js.JSObject.instanceRuntimeType,
+  'JSFunction': () => js.JSFunction.instanceRuntimeType,
+  'JSArray': () => js.JSArray.instanceRuntimeType,
 $!TYPE_MAP
 };
 
 // TODO(leafp): We may want to move this elsewhere if html becomes
 // a package to avoid dartium depending on pkg:html.
+@Deprecated("Internal Use Only")
+getHtmlCreateType(String key) => _getType(key);
+
 Type _getType(String key) {
   var result;
 
@@ -252,102 +256,15 @@ Type _getSvgType(String key) {
   return null;
 }
 
+// TODO(jacobr): it would be nice to place this in a consistent place for dart2js and dartium.
+_convertNativeToDart_XHR_Response(o) {
+  if (o is Document) {
+    return o;
+  }
+  return convertNativeToDart_SerializedScriptValue(o);
+}
+
 $if JSINTEROP
-// FIXME: Can we make this private?
-@Deprecated("Internal Use Only")
-final htmlBlinkFunctionMap = {
-$!TYPE_FUNCTION_MAP
-};
-
-// TODO(terry): We may want to move this elsewhere if html becomes
-// a package to avoid dartium depending on pkg:html.
-@Deprecated("Internal Use Only")
-getHtmlCreateFunction(String key) {
-  var result;
-
-  // TODO(vsm): Add Cross Frame and JS types here as well.
-
-  // Check the html library.
-  result = _getHtmlFunction(key);
-  if (result != null) {
-    return result;
-  }
-
-  // Check the web gl library.
-  result = _getWebGlFunction(key);
-  if (result != null) {
-    return result;
-  }
-
-  // Check the indexed db library.
-  result = _getIndexDbFunction(key);
-  if (result != null) {
-    return result;
-  }
-
-  // Check the web audio library.
-  result = _getWebAudioFunction(key);
-  if (result != null) {
-    return result;
-  }
-
-  // Check the web sql library.
-  result = _getWebSqlFunction(key);
-  if (result != null) {
-    return result;
-  }
-
-  // Check the svg library.
-  result = _getSvgFunction(key);
-  if (result != null) {
-    return result;
-  }
-
-  return null;
-}
-
-Function _getHtmlFunction(String key) {
-  if (htmlBlinkFunctionMap.containsKey(key)) {
-    return htmlBlinkFunctionMap[key]();
-  }
-  return null;
-}
-
-Function _getWebGlFunction(String key) {
-  if (web_glBlinkFunctionMap.containsKey(key)) {
-    return web_glBlinkFunctionMap[key]();
-  }
-  return null;
-}
-
-Function _getIndexDbFunction(String key) {
-  if (indexed_dbBlinkFunctionMap.containsKey(key)) {
-    return indexed_dbBlinkFunctionMap[key]();
-  }
-  return null;
-}
-
-Function _getWebAudioFunction(String key) {
-  if (web_audioBlinkFunctionMap.containsKey(key)) {
-    return web_audioBlinkFunctionMap[key]();
-  }
-  return null;
-}
-
-Function _getWebSqlFunction(String key) {
-  if (web_sqlBlinkFunctionMap.containsKey(key)) {
-    return web_sqlBlinkFunctionMap[key]();
-  }
-  return null;
-}
-
-Function _getSvgFunction(String key) {
-  if (svgBlinkFunctionMap.containsKey(key)) {
-    return svgBlinkFunctionMap[key]();
-  }
-  return null;
-}
-
 
 /******************************************************************************
  **********                                                          **********
@@ -368,22 +285,14 @@ String _getCustomElementName(element) {
   var jsObject;
   var tag = "";
   var runtimeType = element.runtimeType;
-  if (runtimeType == HtmlElement) {
+  if (runtimeType == TemplateElement) {
-    tag = element.localName;
-  } else if (runtimeType == TemplateElement) {
     // Data binding with a Dart class.
     tag = element.attributes['is'];
-  } else if (runtimeType == js.JsObject) {
+  } else if (element is HtmlElement) {
-    // It's a Polymer core element (written in JS).
+    tag = element.attributes['is'];
-    // Make sure it's an element anything else we can ignore.
+    if (tag == null) {
-    if (element.hasProperty('nodeType') && element['nodeType'] == 1) {
+      // It's a custom element we want the local name.
-      if (js.JsNative.callMethod(element, 'hasAttribute', ['is'])) {
+      tag = element.localName;
-        // It's data binding use the is attribute.
-        tag = js.JsNative.callMethod(element, 'getAttribute', ['is']);
-      } else {
-        // It's a custom element we want the local name.
-        tag = element['localName'];
-      }
     }
   } else {
     throw new UnsupportedError('Element is incorrect type. Got ${runtimeType}, expected HtmlElement/HtmlTemplate/JsObject.');
@@ -412,12 +321,16 @@ debug_or_assert(message, expression) {
   }
 }
 
+// TODO(jacobr): we shouldn't be generating this call in the dart:html
+// bindings but we are.
+_convertDartToNative_EventTarget(target) => target;
+
 @Deprecated("Internal Use Only")
 Map<String, dynamic> convertNativeObjectToDartMap(js.JsObject jsObject) {
   var result = new Map();
   var keys = js.JsNative.callMethod(js.JsNative.getProperty(js.context, 'Object'), 'keys', [jsObject]);
   for (var key in keys) {
-    result[key] = wrap_jso(js.JsNative.getProperty(jsObject, key));
+    result[key] = js.JsNative.getProperty(jsObject, key);
   }
   return result;
 }
@@ -426,25 +339,7 @@ Map<String, dynamic> convertNativeObjectToDartMap(js.JsObject jsObject) {
  * Upgrade the JS HTMLElement to the Dart class.  Used by Dart's Polymer.
  */
 _createCustomUpgrader(Type customElementClass, $this) {
-  var dartClass;
+  return _blink.Blink_Utils.setInstanceInterceptor($this, customElementClass, customElement: true);
-  try {
-    dartClass = _blink.Blink_Utils.constructElement(customElementClass, $this);
-  } catch (e) {
-    // Did the dartClass get allocated but the created failed?  Otherwise, other
-    // components inside of this failed somewhere (could be JS custom element).
-    if (dartClass != null) {
-      // Yes, mark as didn't upgrade.
-      dartClass._badUpgrade();
-    }
-    throw e;
-  } finally {
-    // Need to remember the Dart class that was created for this custom so
-    // return it and setup the blink_jsObject to the $this that we'll be working
-    // with as we talk to blink.
-    js.setDartHtmlWrapperFor($this, dartClass);
-  }
-
-  return dartClass;
 }
 
 $else

tools/dom/templates/html/dartium/indexed_db_dartium.darttemplate

@@ -112,10 +112,66 @@ final indexed_dbBlinkMap = {
 $!TYPE_MAP
 };
 
-$if JSINTEROP
+
-// FIXME: Can we make this private?
+//
-@Deprecated("Internal Use Only")
+// Per http://www.w3.org/TR/IndexedDB/#key-construct
-final indexed_dbBlinkFunctionMap = {
+//
-$!TYPE_FUNCTION_MAP
+// "A value is said to be a valid key if it is one of the following types: Array
-};
+// JavaScript objects [ECMA-262], DOMString [WEBIDL], Date [ECMA-262] or float
-$endif
+// [WEBIDL]. However Arrays are only valid keys if every item in the array is
+// defined and is a valid key (i.e. sparse arrays can not be valid keys) and if
+// the Array doesn't directly or indirectly contain itself. Any non-numeric
+// properties are ignored, and thus does not affect whether the Array is a valid
+// key. Additionally, if the value is of type float, it is only a valid key if
+// it is not NaN, and if the value is of type Date it is only a valid key if its
+// [[PrimitiveValue]] internal property, as defined by [ECMA-262], is not NaN."
+
+// What is required is to ensure that an Lists in the key are actually
+// JavaScript arrays, and any Dates are JavaScript Dates.
+
+
+/**
+ * Converts a native IDBKey into a Dart object.
+ *
+ * May return the original input.  May mutate the original input (but will be
+ * idempotent if mutation occurs).  It is assumed that this conversion happens
+ * on native IDBKeys on all paths that return IDBKeys from native DOM calls.
+ *
+ * If necessary, JavaScript Dates are converted into Dart Dates.
+ */
+_convertNativeToDart_IDBKey(nativeKey) {
+  containsDate(object) {
+    if (object is DateTime) return true;
+    if (object is List) {
+      for (int i = 0; i < object.length; i++) {
+        if (containsDate(object[i])) return true;
+      }
+    }
+    return false;  // number, string.
+  }
+  if (nativeKey is DateTime) {
+    throw new UnimplementedError('Key containing DateTime');
+  }
+  // TODO: Cache conversion somewhere?
+  return nativeKey;
+}
+
+/**
+ * Converts a Dart object into a valid IDBKey.
+ *
+ * May return the original input.  Does not mutate input.
+ *
+ * If necessary, [dartKey] may be copied to ensure all lists are converted into
+ * JavaScript Arrays and Dart Dates into JavaScript Dates.
+ */
+_convertDartToNative_IDBKey(dartKey) {
+  // TODO: Implement.
+  return dartKey;
+}
+
+
+
+/// May modify original.  If so, action is idempotent.
+_convertNativeToDart_IDBAny(object) {
+  return convertNativeToDart_AcceptStructuredClone(object, mustCopy: false);
+}

tools/dom/templates/html/dartium/svg_dartium.darttemplate

@@ -28,11 +28,3 @@ $!GENERATED_DART_FILES
 final svgBlinkMap = {
 $!TYPE_MAP
 };
-
-$if JSINTEROP
-// FIXME: Can we make this private?
-@Deprecated("Internal Use Only")
-final svgBlinkFunctionMap = {
-$!TYPE_FUNCTION_MAP
-};
-$endif

tools/dom/templates/html/dartium/web_audio_dartium.darttemplate

@@ -22,11 +22,3 @@ $!GENERATED_DART_FILES
 final web_audioBlinkMap = {
 $!TYPE_MAP
 };
-
-$if JSINTEROP
-// FIXME: Can we make this private?
-@Deprecated("Internal Use Only")
-final web_audioBlinkFunctionMap = {
-$!TYPE_FUNCTION_MAP
-};
-$endif

tools/dom/templates/html/dartium/web_gl_dartium.darttemplate

@@ -24,11 +24,3 @@ $!GENERATED_DART_FILES
 final web_glBlinkMap = {
 $!TYPE_MAP
 };
-
-$if JSINTEROP
-// FIXME: Can we make this private?
-@Deprecated("Internal Use Only")
-final web_glBlinkFunctionMap = {
-$!TYPE_FUNCTION_MAP
-};
-$endif

tools/dom/templates/html/dartium/web_sql_dartium.darttemplate

@@ -30,11 +30,3 @@ $!GENERATED_DART_FILES
 final web_sqlBlinkMap = {
 $!TYPE_MAP
 };
-
-$if JSINTEROP
-// FIXME: Can we make this private?
-@Deprecated("Internal Use Only")
-final web_sqlBlinkFunctionMap = {
-$!TYPE_FUNCTION_MAP
-};
-$endif

tools/dom/templates/html/impl/impl_Blob.darttemplate

@@ -31,15 +31,15 @@ $else
     // TODO: any coercions on the elements of blobParts, e.g. coerce a typed
     // array to ArrayBuffer if it is a total view.
 
-    var parts = convertDartToNative_List(blobParts.map(unwrap_jso).toList());
+    var parts = convertDartToNative_List(blobParts);
     if (type == null && endings == null) {
-      return wrap_jso(_blink.BlinkBlob.instance.constructorCallback_1_(parts));
+      return _blink.BlinkBlob.instance.constructorCallback_1_(parts);
     }
     var bag = {};
     if (type != null) bag['type'] = type;
     if (endings != null) bag['endings'] = endings;
-    return wrap_jso(_blink.BlinkBlob.instance.constructorCallback_2_(parts,
+    return _blink.BlinkBlob.instance.constructorCallback_2_(parts,
-        convertDartToNative_Dictionary(bag)));
+        convertDartToNative_Dictionary(bag));
   }
   $endif
 $endif

tools/dom/templates/html/impl/impl_CSSStyleDeclaration.darttemplate

@@ -63,7 +63,7 @@ $endif
 $if DARTIUM
   bool _hasProperty(String propertyName) =>
   $if JSINTEROP
-      _blink.BlinkCSSStyleDeclaration.instance.$__propertyQuery___Callback_1_(unwrap_jso(this), propertyName) != null;
+      _blink.BlinkCSSStyleDeclaration.instance.$__propertyQuery___Callback_1_(this, propertyName);
   $else
       _blink.BlinkCSSStyleDeclaration.$__propertyQuery___Callback_1(this, propertyName);
   $endif

tools/dom/templates/html/impl/impl_CustomEvent.darttemplate

@@ -23,9 +23,7 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
     // first-chance exceptions. Can expand this list in the future as needed.
     if (detail is List || detail is Map || detail is String || detail is num) {
       try {
-$if DART2JS
         detail = convertDartToNative_SerializedScriptValue(detail);
-$endif
         e._initCustomEvent(type, canBubble, cancelable, detail);
       } catch(_) {
         e._initCustomEvent(type, canBubble, cancelable, null);
@@ -34,11 +32,6 @@ $endif
       e._initCustomEvent(type, canBubble, cancelable, null);
     }
 
-$if DARTIUM
-    // Need for identity.
-    js.setDartHtmlWrapperFor(e.blink_jsObject, e);
-
-$endif
     return e;
   }
 

tools/dom/templates/html/impl/impl_DataTransferItemList.darttemplate

@@ -15,7 +15,7 @@ $else
     // TODO(alanknight): I think that all the __getter__ generators should just
     // do property access, but that's major surgery. This one is a problem, so
     // just hard-code it for now.
-    return _blink.Blink_JsNative_DomException.getProperty(unwrap_jso(this), index);
+    return _blink.Blink_JsNative_DomException.getProperty(this, index);
 $endif
   }
 

tools/dom/templates/html/impl/impl_Document.darttemplate

@@ -68,23 +68,9 @@ $if DART2JS
         ? _createElement_2(tagName)
         : _createElement(tagName, typeExtension);
 $else
-    var newElement = (typeExtension == null) ?
+    return (typeExtension == null) ?
-      _blink.BlinkDocument.instance.createElement_Callback_1_(unwrap_jso(this), tagName) :
+      _blink.BlinkDocument.instance.createElement_Callback_1_(this, tagName) :
-      _blink.BlinkDocument.instance.createElement_Callback_2_(unwrap_jso(this), tagName, typeExtension);
+      _blink.BlinkDocument.instance.createElement_Callback_2_(this, tagName, typeExtension);
-
-    var wrapped = js.getDartHtmlWrapperFor(newElement);  // Here's our Dart class.
-    if (wrapped != null) {
-      wrapped.blink_jsObject = newElement;
-    } else {
-      wrapped = wrap_jso(newElement);
-      if (wrapped == null) {
-        wrapped = wrap_jso_custom_element(newElement);
-      } else {
-        js.setDartHtmlWrapperFor(wrapped.blink_jsObject, wrapped);
-      }
-    }
-
-    return wrapped;
 $endif
   }
 
@@ -110,25 +96,9 @@ $if DART2JS
         ? _createElementNS_2(namespaceURI, qualifiedName)
         : _createElementNS(namespaceURI, qualifiedName, typeExtension);
 $else
-    var newElement = (typeExtension == null) ?
+    return (typeExtension == null) ?
-      _blink.BlinkDocument.instance.createElementNS_Callback_2_(unwrap_jso(this), namespaceURI, qualifiedName) :
+      _blink.BlinkDocument.instance.createElementNS_Callback_2_(this, namespaceURI, qualifiedName) :
-      _blink.BlinkDocument.instance.createElementNS_Callback_3_(unwrap_jso(this), namespaceURI, qualifiedName, typeExtension);
+      _blink.BlinkDocument.instance.createElementNS_Callback_3_(this, namespaceURI, qualifiedName, typeExtension);    
-
-    var wrapped;
-
-    wrapped = js.getDartHtmlWrapperFor(newElement);  // Here's our Dart class.
-    if (wrapped != null) {
-      wrapped.blink_jsObject = newElement;
-    } else {
-      wrapped = wrap_jso(newElement);
-      if (wrapped == null) {
-        wrapped = wrap_jso_custom_element(newElement);
-      } else {
-        js.setDartHtmlWrapperFor(wrapped.blink_jsObject, wrapped);  // Here's our Dart class.
-      }
-    }
-
-    return wrapped;
 $endif
   }
 

tools/dom/templates/html/impl/impl_DocumentType.darttemplate

@@ -9,8 +9,8 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
 $!MEMBERS
 $if DARTIUM
   // Override this methods for Dartium _DocumentType can't be abstract.
-  Element get nextElementSibling => wrap_jso(_blink.BlinkDocumentType.instance.nextElementSibling_Getter_(unwrap_jso(this)));
+  Element get nextElementSibling => _blink.BlinkDocumentType.instance.nextElementSibling_Getter_(this);
-  Element get previousElementSibling => wrap_jso(_blink.BlinkDocumentType.instance.previousElementSibling_Getter_(unwrap_jso(this)));
+  Element get previousElementSibling => _blink.BlinkDocumentType.instance.previousElementSibling_Getter_(this);
 $endif
 }
 

tools/dom/templates/html/impl/impl_Element.darttemplate

@@ -380,7 +380,15 @@ $(ANNOTATIONS)$(NATIVESPEC)class $CLASSNAME$EXTENDS$IMPLEMENTS {
    *     }
    *     document.registerElement('x-custom', CustomElement);
    */
+$if DART2JS
   Element.created() : super._created();
+$else
+  Element.created() : super._created() {
+    // Validate that this is a custom element & possibly perform additional
+    // initialization.
+    _blink.Blink_Utils.initializeCustomElement(this);
+  }
+$endif
 
   /**
    * Creates the HTML element specified by the tag name.
@@ -1483,24 +1491,20 @@ $else
   static var _htmlCollection = js.context["HTMLCollection"];
   static var _nodeList = js.context["NodeList"];
 
+  static const _evilAttributeNames =
+      const ['attributes', 'lastChild', 'children', 'childNodes'];
+
   static bool _hasCorruptedAttributes(Element element) {
-    var attributes = unwrap_jso(element)["attributes"];
+    // We have trusted access to children and to attributes of objects,
-    if (!attributes.instanceof(_namedNodeMap)) {
+    // so we can inspect directly for attempts at DOM clobbering.
-      return true;
+    var child = element.firstChild;
-    }
+    while( child != null)  {
-    var childNodes = unwrap_jso(element.childNodes);
+      if (child is Element) {
-    var length = childNodes["length"];
+      for (var attributeName in ["id", "name"]) {
-    var lastChild = unwrap_jso(element.lastChild);
+        var childAttribute = child.getAttribute(attributeName);
-    if (null != lastChild &&
+        if (_evilAttributeNames.contains(childAttribute)) return true;
-        lastChild != childNodes[length - 1]) {
+      }}
-      return true;
+      child = child.nextNode;
-    }
-    var children = unwrap_jso(element._children);
-    if (null != children) { // On Safari, children can apparently be null.
-      if (!children.instanceof(_htmlCollection) ||
-          children.instanceof(_nodeList)) {
-	return true;
-      }
     }
     return false;
   }
@@ -1509,6 +1513,7 @@ $else
   static bool _hasCorruptedAttributesAdditionalCheck(Element element) => false;
 $endif
 
+$if DART2JS
   static String _safeTagName(element) {
     String result = 'element tag unavailable';
     try {
@@ -1518,6 +1523,15 @@ $endif
     } catch (e) {}
     return result;
   }
+$else
+  static String _safeTagName(element) {
+    try {
+      // Safe as we plumb directly to a C++ native method.
+      return element.tagName;
+    } catch (e) {}
+    return 'element tag unavailable';
+  }
+$endif  
 
 $if DART2JS
   @DomName('Element.offsetParent')
@@ -1570,52 +1584,52 @@ $if DART2JS
 
 $else
   // Need to explicitly delegate because Element is no longer abstract for Dartium.
-  bool get isContentEditable => _blink.BlinkHTMLElement.instance.isContentEditable_Getter_(unwrap_jso(this));
+  bool get isContentEditable => _blink.BlinkHTMLElement.instance.isContentEditable_Getter_(this);
-  void click() => _blink.BlinkHTMLElement.instance.click_Callback_0_(unwrap_jso(this));
+  void click() => _blink.BlinkHTMLElement.instance.click_Callback_0_(this);
 
   @DomName('Element.offsetParent')
   @DocsEditable()
-  Element get offsetParent => wrap_jso(_blink.BlinkElement.instance.offsetParent_Getter_(unwrap_jso(this)));
+  Element get offsetParent => _blink.BlinkElement.instance.offsetParent_Getter_(this);
 
   @DomName('Element.offsetHeight')
   @DocsEditable()
-  int get offsetHeight => _blink.BlinkElement.instance.offsetHeight_Getter_(unwrap_jso(this));
+  int get offsetHeight => _blink.BlinkElement.instance.offsetHeight_Getter_(this);
 
   @DomName('Element.offsetLeft')
   @DocsEditable()
-  int get offsetLeft => _blink.BlinkElement.instance.offsetLeft_Getter_(unwrap_jso(this));
+  int get offsetLeft => _blink.BlinkElement.instance.offsetLeft_Getter_(this);
 
   @DomName('Element.offsetTop')
   @DocsEditable()
-  int get offsetTop => _blink.BlinkElement.instance.offsetTop_Getter_(unwrap_jso(this));
+  int get offsetTop => _blink.BlinkElement.instance.offsetTop_Getter_(this);
 
   @DomName('Element.offsetWidth')
   @DocsEditable()
-  int get offsetWidth => _blink.BlinkElement.instance.offsetWidth_Getter_(unwrap_jso(this));
+  int get offsetWidth => _blink.BlinkElement.instance.offsetWidth_Getter_(this);
 
   @DomName('Element.scrollHeight')
   @DocsEditable()
-  int get scrollHeight => _blink.BlinkElement.instance.scrollHeight_Getter_(unwrap_jso(this)).round();
+  int get scrollHeight => _blink.BlinkElement.instance.scrollHeight_Getter_(this).round();
 
   @DomName('Element.scrollLeft')
   @DocsEditable()
-  int get scrollLeft => _blink.BlinkElement.instance.scrollLeft_Getter_(unwrap_jso(this)).round();
+  int get scrollLeft => _blink.BlinkElement.instance.scrollLeft_Getter_(this).round();
 
   @DomName('Element.scrollLeft')
   @DocsEditable()
-  set scrollLeft(int value) => _blink.BlinkElement.instance.scrollLeft_Setter_(unwrap_jso(this), value.round());
+  set scrollLeft(int value) => _blink.BlinkElement.instance.scrollLeft_Setter_(this, value.round());
 
   @DomName('Element.scrollTop')
   @DocsEditable()
-  int get scrollTop => _blink.BlinkElement.instance.scrollTop_Getter_(unwrap_jso(this)).round();
+  int get scrollTop => _blink.BlinkElement.instance.scrollTop_Getter_(this).round();
 
   @DomName('Element.scrollTop')
   @DocsEditable()
-  set scrollTop(int value) => _blink.BlinkElement.instance.scrollTop_Setter_(unwrap_jso(this), value.round());
+  set scrollTop(int value) => _blink.BlinkElement.instance.scrollTop_Setter_(this, value.round());
 
   @DomName('Element.scrollWidth')
   @DocsEditable()
-  int get scrollWidth => _blink.BlinkElement.instance.scrollWidth_Getter_(unwrap_jso(this)).round();
+  int get scrollWidth => _blink.BlinkElement.instance.scrollWidth_Getter_(this).round();
 $endif
 
 $!MEMBERS

tools/dom/templates/html/impl/impl_FileReader.darttemplate

@@ -13,7 +13,7 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
 $if DART2JS
     var res = JS('Null|String|NativeByteBuffer', '#.result', this);
 $else
-    var res = _blink.BlinkFileReader.instance.result_Getter_(unwrap_jso(this));
+    var res = _blink.BlinkFileReader.instance.result_Getter_(this);
 $endif
     if (res is ByteBuffer) {
       return new Uint8List.view(res);

tools/dom/templates/html/impl/impl_HTMLAudioElement.darttemplate

@@ -10,9 +10,9 @@ $!MEMBERS
 $if JSINTEROP
   factory AudioElement([String src]) {
     if (src == null)
-      return wrap_jso(_blink.BlinkHTMLAudioElement.instance.constructorCallback_0_());
+      return _blink.BlinkHTMLAudioElement.instance.constructorCallback_0_();
     else
-      return wrap_jso(_blink.BlinkHTMLAudioElement.instance.constructorCallback_1_(src));
+      return _blink.BlinkHTMLAudioElement.instance.constructorCallback_1_(src);
   }
 $else
   factory AudioElement([String src]) => new AudioElement._(src);

tools/dom/templates/html/impl/impl_HTMLDocument.darttemplate

@@ -413,9 +413,6 @@ $else
       }
       var elemProto = js.JsNative.callMethod(js.JsNative.getProperty(js.context, 'Object'), "create", [js.JsNative.getProperty(baseElement, 'prototype')]);
 
-      // Remember for any upgrading done in wrap_jso.
-      addCustomElementType(tag, customElementClass, extendsTag);
-
       // TODO(terry): Hack to stop recursion re-creating custom element when the
       //              created() constructor of the custom element does e.g.,
       //
@@ -427,77 +424,42 @@ $else
       //              until stack overflow.
       //
       //              See https://github.com/dart-lang/sdk/issues/23666
-      int creating = 0;
+      int creating = 0; // TODO(jacobr): I think I broke thise case. Will fix monday.
 
       // If any JS code is hooked we want to call it too.
-      var oldCreatedCallback = elemProto['createdCallback'];
+      var oldCreatedCallback = js.JsNative.getProperty(elemProto, 'createdCallback');
-      var oldAttributeChangedCallback = elemProto['attributeChangedCallback'];
+      var oldAttributeChangedCallback = js.JsNative.getProperty(elemProto, 'attributeChangedCallback');
-      var oldAttachedCallback = elemProto['attachedCallback'];
+      var oldAttachedCallback = js.JsNative.getProperty(elemProto, 'attachedCallback');
-      var oldDetachedCallback = elemProto['detachedCallback'];
+      var oldDetachedCallback = js.JsNative.getProperty(elemProto, 'detachedCallback');
-
-      // TODO(jacobr): warning:
-      elemProto['createdCallback'] = js.JsNative.withThis(($this) {
-        if (_getJSClassName(reflectClass(customElementClass).superclass) != null && creating < 2) {
-          creating++;
-
-          var dartClass;
-          try {
-            if (extendsTag != null) {
-              // If we're extending a native element then create that element.
-              // Then upgrade that element to the customElementClass through
-              // normal flow.
-              dartClass = document.createElement(extendsTag);
-              js.setDartHtmlWrapperFor($this, dartClass);
-              dartClass.blink_jsObject = $this;
-            }
-
-            // Upgrade to the CustomElement Dart class.
-            dartClass = _blink.Blink_Utils.constructElement(customElementClass, $this);
-          } catch (e) {
-            // Got a problem make it an HtmlElement and rethrow the error.
-            dartClass = HtmlElement.internalCreateHtmlElement();
-            // We need to remember the JS object (because constructElement failed
-            // it normally sets up the blink_jsObject.
-            dartClass.blink_jsObject = $this;
-
-            // Mark to only try this once don't try upgrading from HtmlElement
-            // to the user's Dart class - we had a problem.
-            dartClass._badUpgrade();
-            throw e;
-          } finally {
-            // Need to remember the Dart class that was created for this custom so
-            // return it and setup the blink_jsObject to the $this that we'll be working
-            // with as we talk to blink.
-            js.setDartHtmlWrapperFor($this, dartClass);
-
-            creating--;
-          }
-        }
 
+      js.JsNative.setProperty(elemProto, 'createdCallback', js.allowInteropCaptureThis(($this) {
+        // The created callback has already been called by the very act of passing a JS
+        // custom element from JS to Dart.
         if (oldCreatedCallback != null)
-          oldCreatedCallback.apply([], thisArg: unwrap_jso($this));
+          oldCreatedCallback.apply([], thisArg: $this);
-      });
+      }));
-      elemProto['attributeChangedCallback'] = new js.JsFunction.withThis(($this, attrName, oldVal, newVal) {
+      js.JsNative.setProperty(elemProto, 'attributeChangedCallback', js.allowInteropCaptureThis(($this, attrName, oldVal, newVal) {
         $this.attributeChanged(attrName, oldVal, newVal);
 
         if (oldAttributeChangedCallback != null)
-          oldAttributeChangedCallback.apply([], thisArg: unwrap_jso($this));
+          oldAttributeChangedCallback.apply([], thisArg: $this);
-      });
+      }));
-      elemProto['attachedCallback'] = new js.JsFunction.withThis(($this) {
+      js.JsNative.setProperty(elemProto, 'attachedCallback', js.allowInteropCaptureThis(($this) {
         $this.attached();
 
         if (oldAttachedCallback != null)
-          oldAttachedCallback.apply([], thisArg: unwrap_jso($this));
+          oldAttachedCallback.apply([], thisArg: $this);
-      });
+      }));
-      elemProto['detachedCallback'] = new js.JsFunction.withThis(($this) {
+      js.JsNative.setProperty(elemProto, 'detachedCallback', js.allowInteropCaptureThis(($this) {
         $this.detached();
 
         if (oldDetachedCallback != null)
-          oldDetachedCallback.apply([], thisArg: unwrap_jso($this));
+          oldDetachedCallback.apply([], thisArg: $this);
-      });
+      }));
       // document.registerElement('x-foo', {prototype: elemProto, extends: extendsTag});
       var jsMap = new js.JsObject.jsify({'prototype': elemProto, 'extends': extendsTag});
-      js.JsNative.callMethod(js.JsNative.getProperty(js.context, 'document'), 'registerElement', [tag, jsMap]);
+      _blink.Blink_Utils.defineInterceptorCustomElement(elemProto, customElementClass);
+      js.JsNative.callMethod(document, 'registerElement', [tag, jsMap]);
     }
 $endif
   }

tools/dom/templates/html/impl/impl_HTMLElement.darttemplate

@@ -7,18 +7,4 @@ part of $LIBRARYNAME;
 @DocsEditable()
 $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS {
 $!MEMBERS
-$if DARTIUM
-  // Flags to only try upgrading once. If there's a failure don't try upgrading
-  // anymore.
-  bool _badUpgradeOccurred = false;
-
-  /// Required for SDK Infrastructure. Internal use only.
-  ///
-  /// Did this encounter a failure attempting to upgrade to
-  /// a custom element.
-  @Deprecated("Required for SDK Infrastructure. Internal use only.")
-  bool get isBadUpgrade => _badUpgradeOccurred;
-
-  void _badUpgrade() { _badUpgradeOccurred = true; }
-$endif
 }

tools/dom/templates/html/impl/impl_IDBDatabase.darttemplate

@@ -72,14 +72,14 @@ $else
     if (storeName_OR_storeNames == null) {
       throw new ArgumentError("stores may not be null in transaction");
     } else if (storeName_OR_storeNames is String || storeName_OR_storeNames is DomStringList) {
-      names = unwrap_jso(storeName_OR_storeNames);
+      names = storeName_OR_storeNames;
     } else if (storeName_OR_storeNames is List<String>) {
       names = convertDartToNative_List(storeName_OR_storeNames);
     } else {
       throw new ArgumentError("Invalid store(s) $store_Name_OR_storeNames");
     }
 
-    return wrap_jso(_blink.BlinkIDBDatabase.instance.transaction_Callback_2_(unwrap_jso(this), names, mode));
+    return _blink.BlinkIDBDatabase.instance.transaction_Callback_2_(this, names, mode);
   }
 
   Transaction transactionList(List<String> storeNames, String mode) => transaction(storeNames, mode);

tools/dom/templates/html/impl/impl_MessageEvent.darttemplate

@@ -35,7 +35,7 @@ $if DARTIUM
   @DomName('MessageEvent.data')
   @DocsEditable()
   dynamic get data => convertNativeToDart_SerializedScriptValue(
-      _blink.BlinkMessageEvent.instance.data_Getter_(unwrap_jso(this)));
+      _blink.BlinkMessageEvent.instance.data_Getter_(this));
 
 $else
   // TODO(alanknight): This really should be generated by the

tools/dom/templates/html/impl/impl_MutationObserver.darttemplate

@@ -20,13 +20,7 @@ $endif
   }
 $if DARTIUM
   @DocsEditable()
-  $if JSINTEROP
-  static MutationObserver _create(callback) => wrap_jso(_blink.BlinkMutationObserver.instance.constructorCallback_1_((mutations, observer) {
-    callback(wrap_jso(mutations), wrap_jso(observer));
-  }));
-  $else
   static MutationObserver _create(callback) => _blink.BlinkMutationObserver.instance.constructorCallback_1_(callback);
-  $endif
 $endif
 
   /**

tools/dom/templates/html/impl/impl_Node.darttemplate

@@ -200,14 +200,7 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
 $if DART2JS
   Node._created() : super._created();
 $else
-  Node._created() : super._created() {
+  Node._created() : super._created();
-    // By this point blink_jsObject should be setup if it's not then we weren't
-    // called by the registerElement createdCallback - probably created() was
-    // called directly which is verboten.
-    if (this.blink_jsObject == null) {
-      throw new DomException.jsInterop("the created constructor cannot be called directly");
-    }
-  }
 $endif
 
   /**
@@ -304,7 +297,7 @@ $if DARTIUM
    */
   @DomName('Node.childNodes')
   @DocsEditable()
-  List<Node> get childNodes => wrap_jso(_blink.BlinkNode.instance.childNodes_Getter_(unwrap_jso(this)));
+  List<Node> get childNodes => _blink.BlinkNode.instance.childNodes_Getter_(this);
 $else
   /**
    * A list of this node's children.

tools/dom/templates/html/impl/impl_SVGCursorElement.darttemplate

@@ -9,11 +9,11 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
 $!MEMBERS
 $if DARTIUM
   // Override these methods for Dartium _SVGCursorElement can't be abstract.
-  StringList get requiredExtensions => wrap_jso(_blink.BlinkSVGCursorElement.instance.requiredExtensions_Getter_(unwrap_jso(this)));
+  StringList get requiredExtensions => _blink.BlinkSVGCursorElement.instance.requiredExtensions_Getter_(this);
-  StringList get requiredFeatures => wrap_jso(_blink.BlinkSVGCursorElement.instance.requiredFeatures_Getter_(unwrap_jso(this)));
+  StringList get requiredFeatures => _blink.BlinkSVGCursorElement.instance.requiredFeatures_Getter_(this);
-  StringList get systemLanguage => wrap_jso(_blink.BlinkSVGCursorElement.instance.systemLanguage_Getter_(unwrap_jso(this)));
+  StringList get systemLanguage => _blink.BlinkSVGCursorElement.instance.systemLanguage_Getter_(this);
-  AnimatedString get href => wrap_jso(_blink.BlinkSVGCursorElement.instance.href_Getter_(unwrap_jso(this)));
+  AnimatedString get href => _blink.BlinkSVGCursorElement.instance.href_Getter_(this);
-  bool hasExtension(String extension) => _blink.BlinkSVGCursorElement.instance.hasExtension_Callback_1_(unwrap_jso(this), extension);
+  bool hasExtension(String extension) => _blink.BlinkSVGCursorElement.instance.hasExtension_Callback_1_(this, extension);
 $endif
 }
 

tools/dom/templates/html/impl/impl_SVGElement.darttemplate

@@ -146,18 +146,8 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
 
 $if JSINTEROP
   set _svgClassName(AnimatedString value) =>
-      _blink.BlinkSVGElement.instance.className_Setter_(unwrap_jso(this), unwrap_jso(value));
+      _blink.BlinkSVGElement.instance.className_Setter_(this, value);
 
-  String get className => _svgClassName.baseVal;
-
-  // Unbelievable hack. We can't create an SvgAnimatedString, but we can get
-  // the existing one and change its baseVal. Then we call the blink setter directly
-  // TODO(alanknight): Handle suppressing the SVGAnimated<*> better
-  set className(String s) {
-    var oldClass = _svgClassName;
-    oldClass.baseVal = s;
-    _svgClassName = oldClass;
-  }
 $endif
 $!MEMBERS
 }

tools/dom/templates/html/impl/impl_SVGFEDropShadowElement.darttemplate

@@ -9,11 +9,11 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
 $!MEMBERS
 $if DARTIUM
   // Override these methods for Dartium _SVGFEDropShadowElement can't be abstract.
-  AnimatedLength get height => wrap_jso(_blink.BlinkSVGFEDropShadowElement.instance.height_Getter_(unwrap_jso(this)));
+  AnimatedLength get height => _blink.BlinkSVGFEDropShadowElement.instance.height_Getter_(this);
-  AnimatedString get result => wrap_jso(_blink.BlinkSVGFEDropShadowElement.instance.result_Getter_(unwrap_jso(this)));
+  AnimatedString get result => _blink.BlinkSVGFEDropShadowElement.instance.result_Getter_(this);
-  AnimatedLength get width => wrap_jso(_blink.BlinkSVGFEDropShadowElement.instance.width_Getter_(unwrap_jso(this)));
+  AnimatedLength get width => _blink.BlinkSVGFEDropShadowElement.instance.width_Getter_(this);
-  AnimatedLength get x => wrap_jso(_blink.BlinkSVGFEDropShadowElement.instance.x_Getter_(unwrap_jso(this)));
+  AnimatedLength get x => _blink.BlinkSVGFEDropShadowElement.instance.x_Getter_(this);
-  AnimatedLength get y => wrap_jso(_blink.BlinkSVGFEDropShadowElement.instance.y_Getter_(unwrap_jso(this)));
+  AnimatedLength get y => _blink.BlinkSVGFEDropShadowElement.instance.y_Getter_(this);
 $endif
 }
 

tools/dom/templates/html/impl/impl_SVGGlyphRefElement.darttemplate

@@ -9,7 +9,7 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
 $!MEMBERS
 $if DARTIUM
   // Override these methods for Dartium _SVGGlyphRefElement can't be abstract.
-  AnimatedString get href => wrap_jso(_blink.BlinkSVGGlyphRefElement.instance.href_Getter_(unwrap_jso(this)));
+  AnimatedString get href => _blink.BlinkSVGGlyphRefElement.instance.href_Getter_(this);
 $endif
 }
 

tools/dom/templates/html/impl/impl_SVGMPathElement.darttemplate

@@ -9,7 +9,7 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
 $!MEMBERS
 $if DARTIUM
   // Override these methods for Dartium _SVGMPathElement can't be abstract.
-  AnimatedString get href => wrap_jso(_blink.BlinkSVGMPathElement.instance.href_Getter_(unwrap_jso(this)));
+  AnimatedString get href => _blink.BlinkSVGMPathElement.instance.href_Getter_(this);
 $endif
 }
 

tools/dom/templates/html/impl/impl_ServiceWorkerMessageEvent.darttemplate

@@ -17,7 +17,7 @@ $if DARTIUM
   @DomName('ServiceWorkerMessageEvent.data')
   @DocsEditable()
   dynamic get data => convertNativeToDart_SerializedScriptValue(
-      _blink.BlinkMessageEvent.instance.data_Getter_(unwrap_jso(this)));
+      _blink.BlinkMessageEvent.instance.data_Getter_(this));
 $else
   // TODO(alanknight): This really should be generated by the
   // _OutputConversion in the systemnative.py script, but that doesn't

tools/dom/templates/html/impl/impl_Touch.darttemplate

@@ -20,14 +20,14 @@ $if DART2JS
   int get __radiusX => JS('num', '#.radiusX', this).round();
   int get __radiusY => JS('num', '#.radiusY', this).round();
 $else
-  int get __clientX => _blink.BlinkTouch.instance.clientX_Getter_(unwrap_jso(this)).round();
+  int get __clientX => _blink.BlinkTouch.instance.clientX_Getter_(this).round();
-  int get __clientY => _blink.BlinkTouch.instance.clientY_Getter_(unwrap_jso(this)).round();
+  int get __clientY => _blink.BlinkTouch.instance.clientY_Getter_(this).round();
-  int get __screenX => _blink.BlinkTouch.instance.screenX_Getter_(unwrap_jso(this)).round();
+  int get __screenX => _blink.BlinkTouch.instance.screenX_Getter_(this).round();
-  int get __screenY => _blink.BlinkTouch.instance.screenY_Getter_(unwrap_jso(this)).round();
+  int get __screenY => _blink.BlinkTouch.instance.screenY_Getter_(this).round();
-  int get __pageX => _blink.BlinkTouch.instance.pageX_Getter_(unwrap_jso(this)).round();
+  int get __pageX => _blink.BlinkTouch.instance.pageX_Getter_(this).round();
-  int get __pageY => _blink.BlinkTouch.instance.pageY_Getter_(unwrap_jso(this)).round();
+  int get __pageY => _blink.BlinkTouch.instance.pageY_Getter_(this).round();
-  int get __radiusX => _blink.BlinkTouch.instance.radiusX_Getter_(unwrap_jso(this)).round();
+  int get __radiusX => _blink.BlinkTouch.instance.radiusX_Getter_(this).round();
-  int get __radiusY => _blink.BlinkTouch.instance.radiusY_Getter_(unwrap_jso(this)).round();
+  int get __radiusY => _blink.BlinkTouch.instance.radiusY_Getter_(this).round();
 $endif
 
   @DomName('Touch.clientX')

tools/dom/templates/html/impl/impl_WheelEvent.darttemplate

@@ -44,7 +44,7 @@ $if DART2JS
         type, convertDartToNative_Dictionary(options));
 
 $else
-    return wrap_jso(_blink.BlinkWheelEvent.instance.constructorCallback_2_(type, convertDartToNative_Dictionary(options)));
+    return _blink.BlinkWheelEvent.instance.constructorCallback_2_(type, convertDartToNative_Dictionary(options));
 $endif
   }
 

tools/dom/templates/html/impl/impl_Window.darttemplate

@@ -297,19 +297,19 @@ $if DART2JS
 $else
   @DomName('Window.pageXOffset')
   @DocsEditable()
-  int get pageXOffset => _blink.BlinkWindow.instance.pageXOffset_Getter_(unwrap_jso(this)).round();
+  int get pageXOffset => _blink.BlinkWindow.instance.pageXOffset_Getter_(this).round();
 
   @DomName('Window.pageYOffset')
   @DocsEditable()
-  int get pageYOffset => _blink.BlinkWindow.instance.pageYOffset_Getter_(unwrap_jso(this)).round();
+  int get pageYOffset => _blink.BlinkWindow.instance.pageYOffset_Getter_(this).round();
 
   @DomName('Window.scrollX')
   @DocsEditable()
-  int get scrollX => _blink.BlinkWindow.instance.scrollX_Getter_(unwrap_jso(this)).round();
+  int get scrollX => _blink.BlinkWindow.instance.scrollX_Getter_(this).round();
 
   @DomName('Window.scrollY')
   @DocsEditable()
-  int get scrollY => _blink.BlinkWindow.instance.scrollY_Getter_(unwrap_jso(this)).round();
+  int get scrollY => _blink.BlinkWindow.instance.scrollY_Getter_(this).round();
 $endif
 }
 

tools/dom/templates/html/impl/impl_WorkerLocation.darttemplate

@@ -9,15 +9,15 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
 $!MEMBERS
 $if DARTIUM
   // Override these methods for Dartium _WorkerLocation can't be abstract.
-  String get hash => _blink.BlinkWorkerLocation.instance.hash_Getter_(unwrap_jso(this));
+  String get hash => _blink.BlinkWorkerLocation.instance.hash_Getter_(this);
-  String get host => _blink.BlinkWorkerLocation.instance.host_Getter_(unwrap_jso(this));
+  String get host => _blink.BlinkWorkerLocation.instance.host_Getter_(this);
-  String get hostname => _blink.BlinkWorkerLocation.instance.hostname_Getter_(unwrap_jso(this));
+  String get hostname => _blink.BlinkWorkerLocation.instance.hostname_Getter_(this);
-  String get href => _blink.BlinkWorkerLocation.instance.href_Getter_(unwrap_jso(this));
+  String get href => _blink.BlinkWorkerLocation.instance.href_Getter_(this);
-  String get origin => _blink.BlinkWorkerLocation.instance.origin_Getter_(unwrap_jso(this));
+  String get origin => _blink.BlinkWorkerLocation.instance.origin_Getter_(this);
-  String get pathname => _blink.BlinkWorkerLocation.instance.pathname_Getter_(unwrap_jso(this));
+  String get pathname => _blink.BlinkWorkerLocation.instance.pathname_Getter_(this);
-  String get port => _blink.BlinkWorkerLocation.instance.port_Getter_(unwrap_jso(this));
+  String get port => _blink.BlinkWorkerLocation.instance.port_Getter_(this);
-  String get protocol => _blink.BlinkWorkerLocation.instance.protocol_Getter_(unwrap_jso(this));
+  String get protocol => _blink.BlinkWorkerLocation.instance.protocol_Getter_(this);
-  String get search => _blink.BlinkWorkerLocation.instance.search_Getter_(unwrap_jso(this));
+  String get search => _blink.BlinkWorkerLocation.instance.search_Getter_(this);
 $endif
 }
 

tools/dom/templates/html/impl/impl_WorkerNavigator.darttemplate

@@ -9,15 +9,15 @@ $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS
 $!MEMBERS
 $if DARTIUM
   // Override these methods for Dartium _WorkerNavigator can't be abstract.
-  String get appCodeName => _blink.BlinkWorkerNavigator.instance.appCodeName_Getter_(unwrap_jso(this));
+  String get appCodeName => _blink.BlinkWorkerNavigator.instance.appCodeName_Getter_(this);
-  String get appName => _blink.BlinkWorkerNavigator.instance.appCodeName_Getter_(unwrap_jso(this));
+  String get appName => _blink.BlinkWorkerNavigator.instance.appCodeName_Getter_(this);
-  String get appVersion => _blink.BlinkWorkerNavigator.instance.appVersion_Getter_(unwrap_jso(this));
+  String get appVersion => _blink.BlinkWorkerNavigator.instance.appVersion_Getter_(this);
-  bool get dartEnabled => _blink.BlinkWorkerNavigator.instance.dartEnabled_Getter_(unwrap_jso(this));
+  bool get dartEnabled => _blink.BlinkWorkerNavigator.instance.dartEnabled_Getter_(this);
-  String get platform => _blink.BlinkWorkerNavigator.instance.platform_Getter_(unwrap_jso(this));
+  String get platform => _blink.BlinkWorkerNavigator.instance.platform_Getter_(this);
-  String get product => _blink.BlinkWorkerNavigator.instance.product_Getter_(unwrap_jso(this));
+  String get product => _blink.BlinkWorkerNavigator.instance.product_Getter_(this);
-  String get userAgent => _blink.BlinkWorkerNavigator.instance.userAgent_Getter_(unwrap_jso(this));
+  String get userAgent => _blink.BlinkWorkerNavigator.instance.userAgent_Getter_(this);
-  int get hardwareConcurrency => _blink.BlinkWorkerNavigator.instance.hardwareConcurrency_Getter_(unwrap_jso(this));
+  int get hardwareConcurrency => _blink.BlinkWorkerNavigator.instance.hardwareConcurrency_Getter_(this);
-  bool get onLine => _blink.BlinkWorkerNavigator.instance.onLine_Getter_(unwrap_jso(this));
+  bool get onLine => _blink.BlinkWorkerNavigator.instance.onLine_Getter_(this);
 $endif
 }
 

tools/dom/templates/html/impl/impl_XMLHttpRequest.darttemplate

@@ -404,9 +404,9 @@ $endif
 $if JSINTEROP
   void open(String method, String url, {bool async, String user, String password}) {
     if (async == null && user == null && password == null) {
-      _blink.BlinkXMLHttpRequest.instance.open_Callback_2_(unwrap_jso(this), method, url);
+      _blink.BlinkXMLHttpRequest.instance.open_Callback_2_(this, method, url);
     } else {
-      _blink.BlinkXMLHttpRequest.instance.open_Callback_5_(unwrap_jso(this), method, url, async, user, password);
+      _blink.BlinkXMLHttpRequest.instance.open_Callback_5_(this, method, url, async, user, password);
     }
   }
 $else