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 4ad38bd3e78ff35ffcb35113c10208e78a74fa0c..347b09b78a220a064d9122f5687ab18d5d29cef2 100644
--- a/content/renderer/gpu/render_widget_compositor.h
+++ b/content/renderer/gpu/render_widget_compositor.h
@@ -82,6 +82,10 @@ class CONTENT_EXPORT RenderWidgetCompositor
   // WebLayerTreeView implementation.
   virtual void setRootLayer(const blink::WebLayer& layer);
   virtual void clearRootLayer();
+  virtual void attachCompositorAnimationTimeline(
+      blink::WebCompositorAnimationTimeline* compositor_timeline);
+  virtual void detachCompositorAnimationTimeline(
+      blink::WebCompositorAnimationTimeline* compositor_timeline);
   virtual void setViewportSize(
       const blink::WebSize& unused_deprecated,
       const blink::WebSize& device_viewport_size);