Handle html+mirrors

BUG=
R=sigmund@google.com

Review URL: https://codereview.chromium.org/2296723003 .

pkg/compiler/lib/src/js_backend/backend.dart

@@ -2338,9 +2338,15 @@ class JavaScriptBackend extends Backend {
 
   /// Called when [enqueuer] is empty, but before it is closed.
   bool onQueueEmpty(Enqueuer enqueuer, Iterable<ClassElement> recentClasses) {
-    // Add elements referenced only via custom elements.  Return early if any
-    // elements are added to avoid counting the elements as due to mirrors.
-    customElementsAnalysis.onQueueEmpty(enqueuer);
+    if (!compiler.options.resolveOnly) {
+      // TODO(johnniwinther): The custom element analysis eagerly enqueues
+      // elements on the codegen queue. Change to compute the data needed
+      // instead.
+
+      // Add elements referenced only via custom elements.  Return early if any
+      // elements are added to avoid counting the elements as due to mirrors.
+      customElementsAnalysis.onQueueEmpty(enqueuer);
+    }
     if (!enqueuer.queueIsEmpty) return false;
 
     noSuchMethodRegistry.onQueueEmpty();

tests/compiler/dart2js/serialization/compilation_test_helper.dart

@@ -26,10 +26,13 @@ main(List<String> args) {
         await serializeDartCore(arguments: arguments);
     if (arguments.filename != null) {
       Uri entryPoint = Uri.base.resolve(nativeToUriPath(arguments.filename));
+      SerializationResult result = await serialize(entryPoint,
+          memorySourceFiles: serializedData.toMemorySourceFiles(),
+          resolutionInputs: serializedData.toUris());
       await compile(
           entryPoint,
-          resolutionInputs: serializedData.toUris(),
-          sourceFiles: serializedData.toMemorySourceFiles());
+          resolutionInputs: result.serializedData.toUris(),
+          sourceFiles: result.serializedData.toMemorySourceFiles());
     } else {
       Uri entryPoint = Uri.parse('memory:main.dart');
       await arguments.forEachTest(serializedData, TESTS, compile);
@@ -51,7 +54,7 @@ Future compile(
   OutputCollector outputCollector = new OutputCollector();
   await measure(title, 'compile', () async {
     List<String> options = [];
-    if (test.checkedMode) {
+    if (test != null && test.checkedMode) {
       options.add(Flags.enableCheckedMode);
     }
     await runCompiler(

tests/compiler/dart2js/serialization/helper.dart

@@ -213,6 +213,7 @@ Future<List<SerializedData>> preserializeData(
       test.preserializedSourceFiles.isEmpty) {
     return <SerializedData>[serializedData];
   }
+
   List<Uri> uriList = <Uri>[];
   for (String key in test.preserializedSourceFiles.keys) {
     uriList.add(Uri.parse('memory:$key'));
@@ -222,21 +223,33 @@ Future<List<SerializedData>> preserializeData(
   if (test.unserializedSourceFiles != null) {
     sourceFiles.addAll(test.unserializedSourceFiles);
   }
-  OutputCollector outputCollector = new OutputCollector();
-  Compiler compiler = compilerFor(
-      memorySourceFiles: sourceFiles,
-      resolutionInputs: serializedData.toUris(),
-      options: [Flags.resolveOnly],
-      outputProvider: outputCollector);
-  compiler.librariesToAnalyzeWhenRun = uriList;
-  await compiler.run(null);
-  List<LibraryElement> libraries = <LibraryElement>[];
-  for (Uri uri in uriList) {
-    libraries.add(compiler.libraryLoader.lookupLibrary(uri));
+  Uri additionalDataUri = Uri.parse('memory:additional.data');
+  SerializedData additionalSerializedData;
+  if (test.sourceFiles.isEmpty) {
+    SerializationResult result = await serialize(
+        uriList.first,
+        memorySourceFiles: sourceFiles,
+        resolutionInputs:  serializedData.toUris(),
+        dataUri: additionalDataUri);
+    additionalSerializedData = result.serializedData;
+  } else {
+    OutputCollector outputCollector = new OutputCollector();
+    Compiler compiler = compilerFor(
+        entryPoint: test.sourceFiles.isEmpty ? uriList.first : null,
+        memorySourceFiles: sourceFiles,
+        resolutionInputs: serializedData.toUris(),
+        options: [Flags.resolveOnly],
+        outputProvider: outputCollector);
+    compiler.librariesToAnalyzeWhenRun = uriList;
+    await compiler.run(null);
+    List<LibraryElement> libraries = <LibraryElement>[];
+    for (Uri uri in uriList) {
+      libraries.add(compiler.libraryLoader.lookupLibrary(uri));
+    }
+    additionalSerializedData = new SerializedData(
+        additionalDataUri,
+        outputCollector.getOutput('', 'data'));
   }
-  SerializedData additionalSerializedData = new SerializedData(
-      Uri.parse('memory:additional.data'),
-      outputCollector.getOutput('', 'data'));
   return <SerializedData>[serializedData, additionalSerializedData];
 }
 

tests/compiler/dart2js/serialization/test_data.dart

@@ -762,6 +762,15 @@ var foo;
         'b.dart': '''
 var foo;
 ''',}),
+
+  const Test('html and mirrors', const {},
+      preserializedSourceFiles: const {
+        'main.dart': '''
+import 'dart:html';
+import 'dart:mirrors';
+main() {}
+'''},
+      expectedWarningCount: 1),
 ];
 
 class Test {