anchor.diff:    void _gameUpdated(args) {
       updateElement();
     }
  +
  +  void requestFrame(){
  +    window.webkitRequestAnimationFrame(_onFrame);
  +  }
  +
  +  void _canvas_mouseMove(MouseEvent e){
  +    _mouseLocation = new dartlib.Coordinate(e.offsetX, e.offsetY);
  +  }
  +
  +  void _canvas_mouseOut(MouseEvent e){
  +    _mouseLocation = null;
  +  }
   }
  
positive.code:     final rootElement = new GameElement(540, 540);
      final stage = new Stage(canvasElement, rootElement);
  
      return new GameRoot._internal(stage, rootElement, leftCountDiv, gameStateDiv, clockDiv);
    }
  
    GameRoot._internal(this._stage, this._gameElement,
        this._leftCountDiv, this._gameStateDiv, this._clockDiv) {
      newGame();
      _requestFrame();
    }
  
negative.code: 
    bool _onFrame(int time) {
      _updateClock();
      _stage.draw();
      if(_mouseLocation != null){
        RetainedDebug.borderHitTest(_stage, _mouseLocation);
      }
      _requestFrame();
    }
  
  