Reland r107720 - Enable the new layer animation framework.

ui/gfx/compositor/layer_animation_delegate.h

 // Copyright (c) 2011 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_GFX_COMPOSITOR_LAYER_ANIMATION_DELEGATE_H_
 #define UI_GFX_COMPOSITOR_LAYER_ANIMATION_DELEGATE_H_
 #pragma once
 
 #include "ui/gfx/rect.h"
 #include "ui/gfx/transform.h"
 #include "ui/gfx/compositor/compositor_export.h"
 
 namespace ui {
 
-// LayerAnimation interacts with the Layer using this interface.
+// 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 Transform& transform) = 0;
   virtual void SetOpacityFromAnimation(float opacity) = 0;
   virtual void ScheduleDrawForAnimation() = 0;
   virtual const gfx::Rect& GetBoundsForAnimation() const = 0;
   virtual const Transform& GetTransformForAnimation() const = 0;
   virtual float GetOpacityForAnimation() const = 0;
 
  protected:
   virtual ~LayerAnimationDelegate() {}
 };
 
 }  // namespace ui
 
 #endif  // UI_GFX_COMPOSITOR_LAYER_ANIMATION_DELEGATE_H_