Make Element.animate work in dart2js Chrome

sdk/lib/html/dart2js/html_dart2js.dart

Index: sdk/lib/html/dart2js/html_dart2js.dart
diff --git a/sdk/lib/html/dart2js/html_dart2js.dart b/sdk/lib/html/dart2js/html_dart2js.dart
index 8e2976493468388a1121fe8aad378c759d571485..abc74dfc210fb3993c0bf457e5647dec88fe9ae7 100644
--- a/sdk/lib/html/dart2js/html_dart2js.dart
+++ b/sdk/lib/html/dart2js/html_dart2js.dart
@@ -385,6 +385,9 @@ class AnimationPlayer extends EventTarget {
   // To suppress missing implicit constructor warnings.
   factory AnimationPlayer._() { throw new UnsupportedError("Not supported"); }
 
+  /// Checks if this type is supported on the current platform.
+  static bool get supported => JS('bool', '!!(document.body.animate)');
+
   @DomName('AnimationPlayer.currentTime')
   @DocsEditable()
   @Experimental() // untriaged
@@ -11198,6 +11201,55 @@ abstract class Element extends Node implements GlobalEventHandlers, ParentNode,
   void leftView() {}
 
   /**
+   * Creates a new AnimationEffect object whose target element is the object
+   * on which the method is called, and calls the play() method of the
+   * AnimationTimeline object of the document timeline of the node document
+   * of the element, passing the newly created AnimationEffect as the argument
+   * to the method. Returns an AnimationPlayer for the effect.
+   *
+   * Examples
+   *
+   *       var animation = elem.animate([{"opacity": 75}, {"opacity": 0}], 200);
+   *
+   *       var animation = elem.animate([
+   *         {"transform": "translate(100px, -100%)"},
+   *         {"transform" : "translate(400px, 500px)"}
+   *       ], 1500);  
+   *
+   * The [frames] parameter is an Iterable<Map>, where the
+   * map entries specify CSS animation effects. The
+   * [timing] paramter can be a double, representing the number of milliseconds
+   * for the transition, or a Map with fields corresponding to those
+   * of the [Timing] object.
+   *
+   * This is not yet supported in Dartium.
+  **/
+// TODO(alanknight): Correct above comment once it works in Dartium.
+  @Experimental
+  @SupportedBrowser(SupportedBrowser.CHROME, '36')
+  AnimationPlayer animate(Iterable<Map<String, dynamic>> frames, [timing]) {
+    if (frames is! Iterable || !(frames.every((x) => x is Map))) {
+      throw new ArgumentError("The frames parameter should be a List of Maps "
+          "with frame information");
+    }
+    var convertedFrames = frames;
+    if (convertedFrames is Iterable) {
+      convertedFrames = frames.map(convertDartToNative_Dictionary).toList();
+    }
+    var convertedTiming = timing;
+    if (convertedTiming is Map) {
+      convertedTiming = convertDartToNative_Dictionary(convertedTiming);
+    }
+    return convertedTiming == null
+      ? _animate(convertedFrames)
+      : _animate(convertedFrames, convertedTiming);
+  }
+
+  @DomName('Element.animate')
+  @JSName('animate')
+  @Experimental() // untriaged
+  AnimationPlayer _animate(Object effect, [timing]) native;
+  /**
    * Called by the DOM whenever an attribute on this has been changed.
    */
   void attributeChanged(String name, String oldValue, String newValue) {}
@@ -12673,11 +12725,6 @@ abstract class Element extends Node implements GlobalEventHandlers, ParentNode,
   @DocsEditable()
   final String tagName;
 
-  @DomName('Element.animate')
-  @DocsEditable()
-  @Experimental() // untriaged
-  AnimationPlayer animate(Object effect, [Object timing]) native;
-
   @DomName('Element.blur')
   @DocsEditable()
   void blur() native;