Allow layers to signal that additional sequences are needed before surface destruction

content/browser/compositor/delegated_frame_host.h

Index: content/browser/compositor/delegated_frame_host.h
diff --git a/content/browser/compositor/delegated_frame_host.h b/content/browser/compositor/delegated_frame_host.h
index a789ef6e1f0bc2684e650a6afceb3743bfb55643..6a0596768ed88ebc6c77d9b37263ec74006e5c8b 100644
--- a/content/browser/compositor/delegated_frame_host.h
+++ b/content/browser/compositor/delegated_frame_host.h
@@ -117,6 +117,9 @@ class CONTENT_EXPORT DelegatedFrameHost
   cc::DelegatedFrameProvider* FrameProviderForTesting() const {
     return frame_provider_.get();
   }
+  cc::SurfaceHolder* SurfaceHolderForTesting() const {
+    return surface_holder_.get();
+  }
   cc::SurfaceId SurfaceIdForTesting() const { return surface_id_; }
   void OnCompositingDidCommitForTesting(ui::Compositor* compositor) {
     OnCompositingDidCommit(compositor);
@@ -267,6 +270,7 @@ class CONTENT_EXPORT DelegatedFrameHost
   scoped_ptr<cc::SurfaceIdAllocator> id_allocator_;
   scoped_ptr<cc::SurfaceFactory> surface_factory_;
   cc::SurfaceId surface_id_;
+  scoped_refptr<cc::SurfaceHolder> surface_holder_;
   gfx::Size current_surface_size_;
   cc::ReturnedResourceArray surface_returned_resources_;