CC Animations: Port Impl-only-scrolling to use compositor animation timelines.

cc/animation/animation_timeline.h

Index: cc/animation/animation_timeline.h
diff --git a/cc/animation/animation_timeline.h b/cc/animation/animation_timeline.h
index 3315b89722449805ae7e0d9bc4dcfb648067347a..1d686630dee56bd8d4318742a5aaf742146b0956 100644
--- a/cc/animation/animation_timeline.h
+++ b/cc/animation/animation_timeline.h
@@ -14,6 +14,10 @@
 #include "cc/animation/animation_events.h"
 #include "cc/base/cc_export.h"
 
+namespace gfx {
+class ScrollOffset;
+}
+
 namespace cc {
 
 class AnimationPlayer;
@@ -91,6 +95,14 @@ class CC_EXPORT AnimationTimeline : public base::RefCounted<AnimationTimeline> {
   bool HasAnyAnimation(int layer_id) const;
   bool HasActiveAnimation(int layer_id) const;
 
+  void ScrollAnimationCreate(int layer_id,
+                             const gfx::ScrollOffset& target_offset,
+                             const gfx::ScrollOffset& current_offset);
+  bool ScrollAnimationUpdateTarget(int layer_id,
+                                   const gfx::Vector2dF& scroll_delta,
+                                   const gfx::ScrollOffset& max_scroll_offset,
+                                   base::TimeTicks frame_monotonic_time);
+
  private:
   friend class base::RefCounted<AnimationTimeline>;
 
@@ -117,6 +129,8 @@ class CC_EXPORT AnimationTimeline : public base::RefCounted<AnimationTimeline> {
   scoped_ptr<AnimationRegistrar> animation_registrar_;
   LayerTreeMutatorsClient* layer_tree_mutators_client_;
 
+  scoped_refptr<AnimationPlayer> scroll_offset_animation_player_;
+
   DISALLOW_COPY_AND_ASSIGN(AnimationTimeline);
 };