compositor: Tick the UI animations from cc, instead of from timer callbacks.

ui/compositor/compositor.h

Index: ui/compositor/compositor.h
diff --git a/ui/compositor/compositor.h b/ui/compositor/compositor.h
index e0606c1a8f47d541183c376b6d0a1c341c9a1daf..79bf691c41520057728284ab3f1d4ba9f165fc77 100644
--- a/ui/compositor/compositor.h
+++ b/ui/compositor/compositor.h
@@ -17,6 +17,7 @@
 #include "third_party/skia/include/core/SkColor.h"
 #include "ui/compositor/compositor_export.h"
 #include "ui/compositor/compositor_observer.h"
+#include "ui/compositor/layer_animator_collection.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/size.h"
 #include "ui/gfx/vector2d.h"
@@ -126,7 +127,8 @@ class COMPOSITOR_EXPORT CompositorLock
 // view hierarchy.
 class COMPOSITOR_EXPORT Compositor
     : NON_EXPORTED_BASE(public cc::LayerTreeHostClient),
-      NON_EXPORTED_BASE(public cc::LayerTreeHostSingleThreadClient) {
+      NON_EXPORTED_BASE(public cc::LayerTreeHostSingleThreadClient),
+      NON_EXPORTED_BASE(public LayerAnimatorCollectionDelegate) {
  public:
   Compositor(gfx::AcceleratedWidget widget,
              ui::ContextFactory* context_factory);
@@ -213,7 +215,7 @@ class COMPOSITOR_EXPORT Compositor
   // LayerTreeHostClient implementation.
   virtual void WillBeginMainFrame(int frame_id) OVERRIDE {}
   virtual void DidBeginMainFrame() OVERRIDE {}
-  virtual void Animate(base::TimeTicks frame_begin_time) OVERRIDE {}
+  virtual void Animate(base::TimeTicks frame_begin_time) OVERRIDE;
   virtual void Layout() OVERRIDE;
   virtual void ApplyScrollAndScale(const gfx::Vector2d& scroll_delta,
                                    float page_scale) OVERRIDE {}
@@ -231,6 +233,9 @@ class COMPOSITOR_EXPORT Compositor
   virtual void DidPostSwapBuffers() OVERRIDE;
   virtual void DidAbortSwapBuffers() OVERRIDE;
 
+  // LayerAnimatorCollectionDelegate implementation.
+  virtual void ScheduleAnimationForLayerCollection() OVERRIDE;
+
   int last_started_frame() { return last_started_frame_; }
   int last_ended_frame() { return last_ended_frame_; }
 
@@ -239,6 +244,10 @@ class COMPOSITOR_EXPORT Compositor
   const cc::LayerTreeDebugState& GetLayerTreeDebugState() const;
   void SetLayerTreeDebugState(const cc::LayerTreeDebugState& debug_state);
 
+  LayerAnimatorCollection* layer_animator_collection() {
+    return &layer_animator_collection_;
+  }
+
  private:
   friend class base::RefCounted<Compositor>;
   friend class CompositorLock;
@@ -289,6 +298,8 @@ class COMPOSITOR_EXPORT Compositor
   enum SwapState { SWAP_NONE, SWAP_POSTED, SWAP_COMPLETED };
   SwapState swap_state_;
 
+  LayerAnimatorCollection layer_animator_collection_;
+
   base::WeakPtrFactory<Compositor> schedule_draw_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Compositor);