[WIP] cc: Plumb SurfaceId from clients

content/browser/renderer_host/delegated_frame_host.h

Index: content/browser/renderer_host/delegated_frame_host.h
diff --git a/content/browser/renderer_host/delegated_frame_host.h b/content/browser/renderer_host/delegated_frame_host.h
index f0d6b2423ed5f86d4fb56156219d6b7748c8c45c..6b3e2282481f77bfe342b45002ecffab479bbbfb 100644
--- a/content/browser/renderer_host/delegated_frame_host.h
+++ b/content/browser/renderer_host/delegated_frame_host.h
@@ -99,6 +99,7 @@ class CONTENT_EXPORT DelegatedFrameHost
   ~DelegatedFrameHost() override;
 
   // ui::CompositorObserver implementation.
+  void OnCompositingInitialized(ui::Compositor* compositor) override;
   void OnCompositingDidCommit(ui::Compositor* compositor) override;
   void OnCompositingStarted(ui::Compositor* compositor,
                             base::TimeTicks start_time) override;
@@ -131,6 +132,7 @@ class CONTENT_EXPORT DelegatedFrameHost
   // Public interface exposed to RenderWidgetHostView.
 
   void SwapDelegatedFrame(uint32_t output_surface_id,
+                          const cc::SurfaceId& surface_id,
                           cc::CompositorFrame frame);
   void ClearDelegatedFrame();
   void WasHidden();
@@ -280,7 +282,7 @@ class CONTENT_EXPORT DelegatedFrameHost
   SkColor background_color_;
 
   // State for rendering into a Surface.
-  std::unique_ptr<cc::SurfaceIdAllocator> id_allocator_;
+  uint32_t surface_client_id_;
   std::unique_ptr<cc::SurfaceFactory> surface_factory_;
   cc::SurfaceId surface_id_;
   gfx::Size current_surface_size_;