Reland r107720 - Enable the new layer animation framework.

ui/gfx/compositor/layer_animation_element.h

Index: ui/gfx/compositor/layer_animation_element.h
diff --git a/ui/gfx/compositor/layer_animation_element.h b/ui/gfx/compositor/layer_animation_element.h
index 12697b0531ea6d67330daba8d9c1fa64b394fdb0..961890cb17d9acbb08ae6a77a70bebbeded22627 100644
--- a/ui/gfx/compositor/layer_animation_element.h
+++ b/ui/gfx/compositor/layer_animation_element.h
@@ -71,6 +71,9 @@ class COMPOSITOR_EXPORT LayerAnimationElement {
   // before OnStarted or Progress.
   void Abort();
 
+  // Sets the delegate to the target value.
+  void SetTarget(LayerAnimationDelegate* delegate) const;

[sky, 2011/10/20 20:30:30]

This is an odd way to extract the target value. How about:

 struct TargetValue {
    transform, opacity ...
  };

 GetTargetValue(TargetValue* target_value);

+
   // The properties that the element modifies.
   const AnimatableProperties& properties() const { return properties_; }
 
@@ -82,6 +85,7 @@ class COMPOSITOR_EXPORT LayerAnimationElement {
   // OnProgress.
   virtual void OnStart(LayerAnimationDelegate* delegate) = 0;
   virtual void OnProgress(double t, LayerAnimationDelegate* delegate) = 0;
+  virtual void OnSetTarget(LayerAnimationDelegate* delegate) const = 0;
   virtual void OnAbort() = 0;
 
  private: