cc: Add ScopedReadLockGpuMemoryBuffer

cc/surfaces/surface.cc

Index: cc/surfaces/surface.cc
diff --git a/cc/surfaces/surface.cc b/cc/surfaces/surface.cc
index 73181292cc176e0253e83de0cde55330f40ed5f7..f48fb83747bbd40df160820633b3b00cddfd5ba9 100644
--- a/cc/surfaces/surface.cc
+++ b/cc/surfaces/surface.cc
@@ -48,6 +48,13 @@ void Surface::SetPreviousFrameSurface(Surface* surface) {
   previous_frame_surface_id_ = surface->surface_id();
 }
 
+void Surface::SetGpuMemoryBufferClientId(int gpu_memory_buffer_client_id) {
+  // This should only be set once.
+  DCHECK_EQ(-1, gpu_memory_buffer_client_id_);
+  DCHECK_NE(gpu_memory_buffer_client_id, gpu_memory_buffer_client_id_);
+  gpu_memory_buffer_client_id_ = gpu_memory_buffer_client_id;
+}
+
 void Surface::QueueFrame(std::unique_ptr<CompositorFrame> frame,
                          const DrawCallback& callback) {
   DCHECK(factory_);