fix #27353, support @checked covariant parameters in DDC

Seems pretty straightforward. Just added a simple test for now.

R=leafp@google.com

Review URL: https://codereview.chromium.org/2340463009 .

pkg/dev_compiler/lib/src/compiler/code_generator.dart

@@ -2179,13 +2179,13 @@ class CodeGenerator extends GeneralizingAstVisitor
       // TODO(jmesserly): various problems here, see:
       // https://github.com/dart-lang/dev_compiler/issues/116
       var paramType = param.element.type;
-      if (node is MethodDeclaration && _unsoundCovariant(paramType, true)) {
+      if (node is MethodDeclaration &&
+          (param.element.isCovariant || _unsoundCovariant(paramType, true)) &&
+          !_inWhitelistCode(node)) {
         var castType = _emitType(paramType,
             nameType: options.nameTypeTests || options.hoistTypeTests,
             hoistType: options.hoistTypeTests);
-        if (!_inWhitelistCode(node)) {
-          body.add(js.statement('#._check(#);', [castType, jsParam]));
-        }
+        body.add(js.statement('#._check(#);', [castType, jsParam]));
       }
     }
     return body.isEmpty ? null : _statement(body);

pkg/dev_compiler/pubspec.lock

@@ -159,9 +159,9 @@ packages:
     version: "0.12.0+2"
   meta:
     description:
-      name: meta
-      url: "https://pub.dartlang.org"
-    source: hosted
+      path: "../meta"
+      relative: true
+    source: path
     version: "1.0.3"
   mime:
     description:

pkg/dev_compiler/pubspec.yaml

@@ -16,6 +16,7 @@ dependencies:
   func: ^0.1.0
   html: ^0.12.0
   js: ^0.6.0
+  meta: ^1.0.3
   path: ^1.3.0
   pub_semver: ^1.1.0
   source_maps: ^0.10.0
@@ -31,15 +32,9 @@ dev_dependencies:
   webdriver: ^1.1.0
 
 dependency_overrides:
-  # This is here until we can update package:test and dart_style
-  analyzer:
-    path: ../analyzer
+  # Depend directly on packages in the same repositiory
+  analyzer: { path: ../analyzer }
+  meta: { path: ../meta }
 
 environment:
   sdk: ">=1.12.0 <2.0.0"
-
-executables:
-  # Similar to "analyzer.dart" and its command line "dartanalyzer" we use
-  # "dartdevc".
-  dartdevc: dartdevc
-  dev_compiler: dartdevc

pkg/dev_compiler/test/codegen/language/checked_covariant_overrides_test.dart

@@ -0,0 +1,36 @@
+// Copyright (c) 2016, 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.
+
+import "package:expect/expect.dart";
+import 'package:meta/meta.dart' show checked;
+
+// Test runtime behavior of @checked
+
+class View {
+  addChild(View v) {}
+  transform(View fn(View v)) {}
+}
+class MyView extends View {
+  addChild(@checked MyView v) {}
+  transform(@checked MyView fn(Object v)) {}
+}
+
+main() {
+  dynamic mv = new MyView();
+  dynamic v = new View();
+  
+  mv.addChild(mv);
+  Expect.throws(() => mv.addChild(v));
+
+  mv.transform((_) => new MyView());
+
+  // TODO(jmesserly): these *should* be a cast failures, but DDC is currently
+  // ignoring function type failures w/ a warning at the console...
+
+  // * -> * not a subtype of Object -> MyView
+  // Expect.throws(() => mv.transform((_) => mv));
+
+  // View -> View not a subtype of Object -> MyView
+  // Expect.throws(() => mv.transform((View x) => x));
+}