Revert "Reapply zone tasks."

tools/dom/templates/html/impl/impl_Window.darttemplate

 // 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 $LIBRARYNAME;
 
-typedef void RemoveFrameRequestMapping(int id);
-
-/**
- * The task object representing animation-frame requests.
- *
- * For historical reasons, [Window.requestAnimationFrame] returns an integer
- * to users. However, zone tasks must be unique objects, and an integer can
- * therefore not be used as task object. The [Window] class thus keeps a mapping
- * from the integer ID to the corresponding task object. All zone related
- * operations work on this task object, whereas users of
- * [Window.requestAnimationFrame] only see the integer ID.
- *
- * Since this mapping takes up space, it must be removed when the
- * animation-frame task has triggered. The default implementation does this
- * automatically, but intercepting implementations of `requestAnimationFrame`
- * must make sure to call the [AnimationFrameTask.removeMapping]
- * function that is provided in the task specification.
- *
- * *Experimental*. This class may disappear without notice.
- */
-abstract class AnimationFrameTask {
-  /** The ID that is returned to users. */
-  int get id;
-
-  /** The zone in which the task will run. */
-  Zone get zone;
-
-  /**
-   * Cancels the animation-frame request.
-   *
-   * A call to [Window.cancelAnimationFrame] with an `id` argument equal to [id]
-   * forwards the request to this function.
-   *
-   * Zones that intercept animation-frame requests implement this method so
-   * that they can react to cancelation requests.
-   */
-  void cancel(Window window);
-
-  /**
-   * Maps animation-frame request IDs to their task objects.
-   */
-  static final Map<int, _AnimationFrameTask> _tasks = {};
-
-  /**
-   * Removes the mapping from [id] to [AnimationFrameTask].
-   *
-   * This function must be invoked by user-implemented animation-frame
-   * tasks, before running [callback].
-   *
-   * See [AnimationFrameTask].
-   */
-  static void removeMapping(int id) {
-    _tasks.remove(id);
-  }
-}
-
-class _AnimationFrameTask implements AnimationFrameTask {
-  final int id;
-  final Zone zone;
-  final FrameRequestCallback _callback;
-
-  _AnimationFrameTask(this.id, this.zone, this._callback);
-
-  void cancel(Window window) {
-    window._cancelAnimationFrame(this.id);
-  }
-}
-
-/**
- * The task specification for an animation-frame request.
- *
- * *Experimental*. This class may disappear without notice.
- */
-class AnimationFrameRequestSpecification implements TaskSpecification {
-  /**
-   * The window on which [Window.requestAnimationFrame] was invoked.
-   */
-  final Window window;
-
-  /**
-   * The callback that is executed when the animation-frame is ready.
-   *
-   * Note that the callback hasn't been registered in any zone when the `create`
-   * function (passed to [Zone.createTask]) is invoked.
-   */
-  final FrameRequestCallback callback;
-
-  AnimationFrameRequestSpecification(this.window, this.callback);
-
-  String get name => "dart.html.request-animation-frame";
-  bool get isOneShot => true;
-}
-
 @DocsEditable()
 $if DART2JS
 $(ANNOTATIONS)@Native("Window,DOMWindow")
 $(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS {
 $else
 $(ANNOTATIONS)$(NATIVESPEC)$(CLASS_MODIFIERS)class $CLASSNAME$EXTENDS$IMPLEMENTS {
 $endif
 
   /**
    * Returns a Future that completes just before the window is about to
    * repaint so the user can draw an animation frame.
    *
    * If you need to later cancel this animation, use [requestAnimationFrame]
    * instead.
    *
    * The [Future] completes to a timestamp that represents a floating
    * point value of the number of milliseconds that have elapsed since the page
    * started to load (which is also the timestamp at this call to
    * animationFrame).
    *
    * Note: The code that runs when the future completes should call
    * [animationFrame] again for the animation to continue.
    */
   Future<num> get animationFrame {
     var completer = new Completer<num>.sync();
-    requestAnimationFrame(completer.complete);
+    requestAnimationFrame((time) {
+      completer.complete(time);
+    });
     return completer.future;
   }
 
 $if DART2JS
   /**
    * The newest document in this window.
    *
    * ## Other resources
    *
    * * [Loading web
@@ skipping 67 matching lines @@
    * cancel.
    *
    * Note: The supplied [callback] needs to call [requestAnimationFrame] again
    * for the animation to continue.
    */
   @DomName('Window.requestAnimationFrame')
   int requestAnimationFrame(FrameRequestCallback callback) {
 $if DART2JS
     _ensureRequestAnimationFrame();
 $endif
-    if (identical(Zone.current, Zone.ROOT)) {
-      return _requestAnimationFrame(callback);
-    }
-    var spec = new AnimationFrameRequestSpecification(this, callback);
-    var task = Zone.current.createTask/*<AnimationFrameTask>*/(
-        _createAnimationFrameTask, spec);
-    AnimationFrameTask._tasks[task.id] = task;
-    return task.id;
-  }
-
-  static _AnimationFrameTask _createAnimationFrameTask(
-      AnimationFrameRequestSpecification spec, Zone zone) {
-    var task;
-    var id = spec.window._requestAnimationFrame((num time) {
-      AnimationFrameTask.removeMapping(task.id);
-      zone.runTask(_runAnimationFrame, task, time);
-    });
-    var callback = zone.registerUnaryCallback(spec.callback);
-    task = new _AnimationFrameTask(id, zone, callback);
-    return task;
-  }
-
-  static void _runAnimationFrame(_AnimationFrameTask task, num time) {
-    task._callback(time);
+    return _requestAnimationFrame(_wrapZone/*<num, dynamic>*/(callback));
   }
 
   /**
    * Cancels an animation frame request.
    *
    * ## Other resources
    *
    * * [Window.cancelAnimationFrame](https://developer.mozilla.org/en-US/docs/Web/API/Window.cancelAnimationFrame)
    *   from MDN.
    */
   @DomName('Window.cancelAnimationFrame')
   void cancelAnimationFrame(int id) {
 $if DART2JS
     _ensureRequestAnimationFrame();
 $endif
-    var task = AnimationFrameTask._tasks.remove(id);
-    if (task == null) {
-      // Assume that the animation frame request wasn't intercepted by a zone.
-      _cancelAnimationFrame(id);
-      return;
-    }
-    task.cancel(this);
+    _cancelAnimationFrame(id);
   }
 
 $if DART2JS
   @JSName('requestAnimationFrame')
   int _requestAnimationFrame(FrameRequestCallback callback) native;
 
   @JSName('cancelAnimationFrame')
   void _cancelAnimationFrame(int id) native;
 
   _ensureRequestAnimationFrame() {
@@ skipping 212 matching lines @@
       {bool useCapture: false}) {
 $if DART2JS
     // Specify the generic type for _ElementEventStreamImpl only in dart2js to
     // avoid checked mode errors in dartium.
     return new _ElementListEventStreamImpl<BeforeUnloadEvent>(e, _eventType, useCapture);
 $else
     return new _ElementListEventStreamImpl(e, _eventType, useCapture);
 $endif
   }
 }