Add callback when queueing frame on Surface to create backpressure.

cc/surfaces/surface_factory.h

Index: cc/surfaces/surface_factory.h
diff --git a/cc/surfaces/surface_factory.h b/cc/surfaces/surface_factory.h
index c74f973d31e0d91bf96f8249b652abb3b3bf8eb2..d9b3e443bcbfd86408791c534aa1a86c1c6acc2b 100644
--- a/cc/surfaces/surface_factory.h
+++ b/cc/surfaces/surface_factory.h
@@ -5,6 +5,7 @@
 #ifndef CC_SURFACES_SURFACE_FACTORY_H_
 #define CC_SURFACES_SURFACE_FACTORY_H_
 
+#include "base/callback_forward.h"
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
@@ -37,7 +38,9 @@ class CC_SURFACES_EXPORT SurfaceFactory
   void Destroy(SurfaceId surface_id);
   // A frame can only be submitted to a surface created by this factory,
   // although the frame may reference surfaces created by other factories.
-  void SubmitFrame(SurfaceId surface_id, scoped_ptr<CompositorFrame> frame);
+  void SubmitFrame(SurfaceId surface_id,

[jamesr, 2014/08/22 06:00:12]

can you document when the callback fires?

+                   scoped_ptr<CompositorFrame> frame,
+                   const base::Closure& callback);
 
   SurfaceFactoryClient* client() { return client_; }