compositor-worker: cc->blink mutation plumbing

content/renderer/gpu/render_widget_compositor_delegate.h

Index: content/renderer/gpu/render_widget_compositor_delegate.h
diff --git a/content/renderer/gpu/render_widget_compositor_delegate.h b/content/renderer/gpu/render_widget_compositor_delegate.h
index 94ed1e68c5df39396865e0ca44a7c603cf1c2fb3..e84b2bc4fb20005d863f62210811bb8a360af93c 100644
--- a/content/renderer/gpu/render_widget_compositor_delegate.h
+++ b/content/renderer/gpu/render_widget_compositor_delegate.h
@@ -15,6 +15,7 @@ struct WebScreenInfo;
 namespace cc {
 class BeginFrameSource;
 class OutputSurface;
+struct LayerTreeMutations;
 }
 
 namespace content {
@@ -32,6 +33,9 @@ class CONTENT_EXPORT RenderWidgetCompositorDelegate {
       float page_scale,
       float top_controls_delta) = 0;
 
+  // Report layer tree mutations from compositor workers during a commit.
+  virtual void ApplyMutations(const cc::LayerTreeMutations& mutations) = 0;
+
   // Notifies that the compositor has issed a BeginMainFrame.
   virtual void BeginMainFrame(double frame_time_sec) = 0;