CC Animations: Establish AnimationHost, AnimationTimeline and AnimationPlayer

content/renderer/gpu/render_widget_compositor.h

Index: content/renderer/gpu/render_widget_compositor.h
diff --git a/content/renderer/gpu/render_widget_compositor.h b/content/renderer/gpu/render_widget_compositor.h
index 25d9f5353543c8739f8e75bb4b628f4443f87df0..b7bfb78e13311eaec5cbe9f6125536a188f4fee2 100644
--- a/content/renderer/gpu/render_widget_compositor.h
+++ b/content/renderer/gpu/render_widget_compositor.h
@@ -86,6 +86,8 @@ class CONTENT_EXPORT RenderWidgetCompositor
   // WebLayerTreeView implementation.
   virtual void setRootLayer(const blink::WebLayer& layer);
   virtual void clearRootLayer();
+  virtual void setCompositorAnimationTimeline(
+      blink::WebCompositorAnimationTimeline* compositor_timeline);
   virtual void setViewportSize(
       const blink::WebSize& unused_deprecated,
       const blink::WebSize& device_viewport_size);