Use Surfaces to hold delegated renderer contents.

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 a7404723608e94ac6d9d078f5dc6a580deb71436..1dc2dd2b19f785304462626d0846be091ff5479a 100644
--- a/content/browser/compositor/delegated_frame_host.h
+++ b/content/browser/compositor/delegated_frame_host.h
@@ -8,6 +8,7 @@
 #include "cc/layers/delegated_frame_provider.h"
 #include "cc/layers/delegated_frame_resource_collection.h"
 #include "cc/output/copy_output_result.h"
+#include "cc/surfaces/surface_factory_client.h"
 #include "content/browser/compositor/image_transport_factory.h"
 #include "content/browser/compositor/owned_mailbox.h"
 #include "content/browser/renderer_host/delegated_frame_evictor.h"
@@ -21,6 +22,10 @@
 #include "ui/compositor/layer_owner_delegate.h"
 #include "ui/gfx/rect_conversions.h"
 
+namespace cc {
+class SurfaceFactory;
+}
+
 namespace media {
 class VideoFrame;
 }
@@ -72,6 +77,7 @@ class CONTENT_EXPORT DelegatedFrameHost
       public ImageTransportFactoryObserver,
       public DelegatedFrameEvictorClient,
       public cc::DelegatedFrameResourceCollectionClient,
+      public cc::SurfaceFactoryClient,
       public base::SupportsWeakPtr<DelegatedFrameHost> {
  public:
   DelegatedFrameHost(DelegatedFrameHostClient* client);
@@ -212,10 +218,18 @@ class CONTENT_EXPORT DelegatedFrameHost
   // cc::DelegatedFrameProviderClient implementation.
   virtual void UnusedResourcesAreAvailable() OVERRIDE;
 
+  // cc::SurfaceFactoryClient implementation.
+  virtual void ReturnResources(
+      const cc::ReturnedResourceArray& resources) OVERRIDE;
+
   void DidReceiveFrameFromRenderer();
 
   DelegatedFrameHostClient* client_;
 
+  // True if this renders into a Surface, false if it renders into a delegated
+  // layer.
+  bool use_surfaces_;
+
   std::vector<base::Closure> on_compositing_did_commit_callbacks_;
 
   // The vsync manager we are observing for changes, if any.
@@ -243,6 +257,12 @@ class CONTENT_EXPORT DelegatedFrameHost
   // Provides delegated frame updates to the cc::DelegatedRendererLayer.
   scoped_refptr<cc::DelegatedFrameProvider> frame_provider_;
 

[ccameron, 2014/07/25 22:28:05]

Might wanna throw a comment saying "State for rendering into a surface" above
this block.

+  scoped_ptr<cc::SurfaceIdAllocator> id_allocator_;
+  scoped_ptr<cc::SurfaceFactory> surface_factory_;
+  cc::SurfaceId surface_id_;
+  gfx::Size current_surface_size_;
+  cc::ReturnedResourceArray surface_returned_resources_;
+
   // This lock is the one waiting for a frame of the right size to come back
   // from the renderer/GPU process. It is set from the moment the aura window
   // got resized, to the moment we committed the renderer frame of the same