CC Animations: Make ui::LayerAnimator a LayerAnimationEventObserver (instead of ui::Layer)

ui/compositor/layer_animation_delegate.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef UI_COMPOSITOR_LAYER_ANIMATION_DELEGATE_H_
 #define UI_COMPOSITOR_LAYER_ANIMATION_DELEGATE_H_
 
 #include "base/memory/scoped_ptr.h"
 #include "cc/animation/animation.h"
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/compositor/compositor_export.h"
 #include "ui/gfx/geometry/rect.h"
 #include "ui/gfx/transform.h"
 
+namespace cc {
+class Layer;
+}
+
 namespace ui {
 
 class LayerAnimatorCollection;
 
 // Layer animations interact with the layers using this interface.
 class COMPOSITOR_EXPORT LayerAnimationDelegate {
  public:
   virtual void SetBoundsFromAnimation(const gfx::Rect& bounds) = 0;
   virtual void SetTransformFromAnimation(const gfx::Transform& transform) = 0;
   virtual void SetOpacityFromAnimation(float opacity) = 0;
   virtual void SetVisibilityFromAnimation(bool visibility) = 0;
   virtual void SetBrightnessFromAnimation(float brightness) = 0;
   virtual void SetGrayscaleFromAnimation(float grayscale) = 0;
   virtual void SetColorFromAnimation(SkColor color) = 0;
   virtual void ScheduleDrawForAnimation() = 0;
   virtual const gfx::Rect& GetBoundsForAnimation() const = 0;
   virtual gfx::Transform GetTransformForAnimation() const = 0;
   virtual float GetOpacityForAnimation() const = 0;
   virtual bool GetVisibilityForAnimation() const = 0;
   virtual float GetBrightnessForAnimation() const = 0;
   virtual float GetGrayscaleForAnimation() const = 0;
   virtual SkColor GetColorForAnimation() const = 0;
   virtual float GetDeviceScaleFactor() const = 0;
   virtual void AddThreadedAnimation(scoped_ptr<cc::Animation> animation) = 0;
   virtual void RemoveThreadedAnimation(int animation_id) = 0;
   virtual LayerAnimatorCollection* GetLayerAnimatorCollection() = 0;
+  virtual cc::Layer* GetCcLayer() const = 0;
 
  protected:
   virtual ~LayerAnimationDelegate() {}
 };
 
 }  // namespace ui
 
 #endif  // UI_COMPOSITOR_LAYER_ANIMATION_DELEGATE_H_