Add callback when queueing frame on Surface to create backpressure.

cc/surfaces/surface_factory.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "cc/surfaces/surface_factory.h"
 
 #include "cc/output/compositor_frame.h"
 #include "cc/surfaces/surface.h"
 #include "cc/surfaces/surface_manager.h"
 #include "ui/gfx/geometry/size.h"
@@ skipping 17 matching lines @@
 
 void SurfaceFactory::Destroy(SurfaceId surface_id) {
   OwningSurfaceMap::iterator it = surface_map_.find(surface_id);
   DCHECK(it != surface_map_.end());
   DCHECK(it->second->factory() == this);
   manager_->DeregisterSurface(surface_id);
   surface_map_.erase(it);
 }
 
 void SurfaceFactory::SubmitFrame(SurfaceId surface_id,
-                                 scoped_ptr<CompositorFrame> frame) {
+                                 scoped_ptr<CompositorFrame> frame,
+                                 const base::Closure& callback) {
   OwningSurfaceMap::iterator it = surface_map_.find(surface_id);
   DCHECK(it != surface_map_.end());
   DCHECK(it->second->factory() == this);
   it->second->QueueFrame(frame.Pass());
+  if (!callback.is_null())

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

can we instead just pass this as a parameter to QueueFrame() since the callback
is logically tied to that frame? means that the null check will be inside
Surface::QueueFrame but that seems fine

+    it->second->AddDrawCallback(callback);
   manager_->SurfaceModified(surface_id);
 }
 
 void SurfaceFactory::ReceiveFromChild(
     const TransferableResourceArray& resources) {
   holder_.ReceiveFromChild(resources);
 }
 
 void SurfaceFactory::RefResources(const TransferableResourceArray& resources) {
   holder_.RefResources(resources);
 }
 
 void SurfaceFactory::UnrefResources(const ReturnedResourceArray& resources) {
   holder_.UnrefResources(resources);
 }
 
 }  // namespace cc