Add callback when queueing frame on Surface to create backpressure.

cc/surfaces/surface_factory.cc

Index: cc/surfaces/surface_factory.cc
diff --git a/cc/surfaces/surface_factory.cc b/cc/surfaces/surface_factory.cc
index d17e98ecad71cfc138dde54be8ee9e48ecf4e1d5..a6478954608d09e40c7550f00ec84e4a4ec9c117 100644
--- a/cc/surfaces/surface_factory.cc
+++ b/cc/surfaces/surface_factory.cc
@@ -35,11 +35,14 @@ void SurfaceFactory::Destroy(SurfaceId surface_id) {
 }
 
 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);
 }