Adding annotation for partial browser support and example implementation for MutationObservers.

sdk/lib/html/dart2js/html_dart2js.dart

 library html;
 
 import 'dart:collection';
 import 'dart:html_common';
 import 'dart:indexed_db';
 import 'dart:isolate';
 import 'dart:json';
 import 'dart:svg' as svg;
 import 'dart:web_audio' as web_audio;
 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
@@ skipping 13247 matching lines @@
 
   /// @domName MutationEvent.initMutationEvent; @docsEditable true
   void initMutationEvent(String type, bool canBubble, bool cancelable, Node relatedNode, String prevValue, String newValue, String attrName, int attrChange) native;
 }
 // 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.
 
 
 /// @domName MutationObserver
+@SupportedBrowser(SupportedBrowser.CHROME)
+@SupportedBrowser(SupportedBrowser.FIREFOX)
+@SupportedBrowser(SupportedBrowser.SAFARI)
+@Experimental()
 class MutationObserver native "*MutationObserver" {
 
   ///@docsEditable true
   factory MutationObserver(MutationCallback callback) => _MutationObserverFactoryProvider.createMutationObserver(callback);
 
   /// @domName MutationObserver.disconnect; @docsEditable true
   void disconnect() native;
 
   /// @domName MutationObserver._observe; @docsEditable true
   void _observe(Node target, Map options) {
     var options_1 = convertDartToNative_Dictionary(options);
     __observe_1(target, options_1);
     return;
   }
   @JSName('observe')
   void __observe_1(Node target, options) native;
 
   /// @domName MutationObserver.takeRecords; @docsEditable true
   List<MutationRecord> takeRecords() native;
 
+  /**
+   * Checks to see if the mutation observer API is supported on the current
+   * platform.
+   */
+  static bool get supported {
+    return JS('bool',
+        '!!(window.MutationObserver || window.WebKitMutationObserver)');
+  }
+
   void observe(Node target,
                {Map options,
                 bool childList,
                 bool attributes,
                 bool characterData,
                 bool subtree,
                 bool attributeOldValue,
                 bool characterDataOldValue,
                 List<String> attributeFilter}) {
 
@@ skipping 11375 matching lines @@
 class _MeasurementRequest<T> {
   final ComputeValue computeValue;
   final Completer<T> completer;
   Object value;
   bool exception = false;
   _MeasurementRequest(this.computeValue, this.completer);
 }
 
 typedef void _MeasurementCallback();
 
-
 /**
  * This class attempts to invoke a callback as soon as the current event stack
  * unwinds, but before the browser repaints.
  */
 abstract class _MeasurementScheduler {
   bool _nextMeasurementFrameScheduled = false;
   _MeasurementCallback _callback;
 
   _MeasurementScheduler(this._callback);
 
   /**
    * Creates the best possible measurement scheduler for the current platform.
    */
   factory _MeasurementScheduler.best(_MeasurementCallback callback) {
-    if (_isMutationObserverSupported()) {
+    if (MutationObserver.supported) {
       return new _MutationObserverScheduler(callback);
     }
     return new _PostMessageScheduler(callback);
   }
 
   /**
    * Schedules a measurement callback if one has not been scheduled already.
    */
   void maybeSchedule() {
     if (this._nextMeasurementFrameScheduled) {
@@ skipping 808 matching lines @@
 
 
   static _get(p, m) => JS('var', '#[#]', p, m);
   static _set(p, m, v) => JS('void', '#[#] = #', p, m, v);
 }
 // 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.
 
 
-/**
- * Checks to see if the mutation observer API is supported on the current
- * platform.
- */
-bool _isMutationObserverSupported() =>
-  JS('bool', '!!(window.MutationObserver || window.WebKitMutationObserver)');
-// 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.
-
-
 class _TypedArrayFactoryProvider {
 
   static Float32Array createFloat32Array(int length) => _F32(length);
   static Float32Array createFloat32Array_fromList(List<num> list) =>
       _F32(ensureNative(list));
   static Float32Array createFloat32Array_fromBuffer(ArrayBuffer buffer,
                                   [int byteOffset = 0, int length]) {
     if (length == null) return _F32_2(buffer, byteOffset);
     return _F32_3(buffer, byteOffset, length);
   }
@@ skipping 179 matching lines @@
   T next() {
     if (!hasNext) {
       throw new StateError("No more elements");
     }
     return _array[_pos++];
   }
 
   final List<T> _array;
   int _pos;
 }