CC Animation: Expose TargetProperty enum to be aliased in Blink Platform.

cc/animation/animation_delegate.h

Index: cc/animation/animation_delegate.h
diff --git a/cc/animation/animation_delegate.h b/cc/animation/animation_delegate.h
index 6064c7ebc83b03e7ed597a2ec09db52309020764..732e6937ff7221ef028eca23888cb60f2bc87b3b 100644
--- a/cc/animation/animation_delegate.h
+++ b/cc/animation/animation_delegate.h
@@ -13,15 +13,14 @@ namespace cc {
 class CC_EXPORT AnimationDelegate {
  public:
   virtual void NotifyAnimationStarted(base::TimeTicks monotonic_time,
-                                      Animation::TargetProperty target_property,
+                                      TargetProperty::Type target_property,
                                       int group) = 0;
-  virtual void NotifyAnimationFinished(
-      base::TimeTicks monotonic_time,
-      Animation::TargetProperty target_property,
-      int group) = 0;
+  virtual void NotifyAnimationFinished(base::TimeTicks monotonic_time,
+                                       TargetProperty::Type target_property,
+                                       int group) = 0;
 
   virtual void NotifyAnimationAborted(base::TimeTicks monotonic_time,
-                                      Animation::TargetProperty target_property,
+                                      TargetProperty::Type target_property,
                                       int group) = 0;
 
  protected: