Add Zone support for Timers.

sdk/lib/_internal/compiler/implementation/enqueue.dart

 // Copyright (c) 2012, 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.
 
 part of dart2js;
 
 class EnqueueTask extends CompilerTask {
   final ResolutionEnqueuer resolution;
   final CodegenEnqueuer codegen;
 
@@ skipping 621 matching lines @@
     queue.add(new ResolutionWorkItem(element, itemCompilationContextCreator()));
 
     // Enable isolate support if we start using something from the
     // isolate library, or timers for the async library.
     LibraryElement library = element.getLibrary();
     if (!compiler.hasIsolateSupport()) {
       String uri = library.canonicalUri.toString();
       if (uri == 'dart:isolate') {
         enableIsolateSupport(library);
       } else if (uri == 'dart:async') {
-        ClassElement cls = element.getEnclosingClass();
-        if (cls != null && cls.name == const SourceString('Timer')) {
+        if (element.name == const SourceString('_createTimer') ||
+            element.name == const SourceString('_createPeriodicTimer')) {
           // The [:Timer:] class uses the event queue of the isolate
           // library, so we make sure that event queue is generated.
           enableIsolateSupport(library);
         }
       }
     }
 
     if (element.isGetter() && element.name == Compiler.RUNTIME_TYPE) {
       // Enable runtime type support if we discover a getter called runtimeType.
       // We have to enable runtime type before hitting the codegen, so
@@ skipping 105 matching lines @@
     while(!queue.isEmpty) {
       // TODO(johnniwinther): Find an optimal process order for codegen.
       f(queue.removeLast());
     }
   }
 
   void _logSpecificSummary(log(message)) {
     log('Compiled ${generatedCode.length} methods.');
   }
 }