Use null rather than empty frame to lock Surface resources

cc/surfaces/surface_display_output_surface.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_display_output_surface.h"
 
 #include "base/bind.h"
 #include "cc/output/compositor_frame.h"
 #include "cc/output/compositor_frame_ack.h"
 #include "cc/surfaces/display.h"
@@ skipping 62 matching lines @@
 bool SurfaceDisplayOutputSurface::BindToClient(OutputSurfaceClient* client) {
   DCHECK(client);
   DCHECK(display_client_);
   client_ = client;
   // Avoid initializing GL context here, as this should be sharing the
   // Display's context.
   return display_client_->Initialize();
 }
 
 void SurfaceDisplayOutputSurface::ForceReclaimResources() {
-  if (!surface_id_.is_null()) {
-    scoped_ptr<CompositorFrame> empty_frame(new CompositorFrame());
-    empty_frame->delegated_frame_data.reset(new DelegatedFrameData);
-    factory_.SubmitFrame(surface_id_, empty_frame.Pass(),
-                         SurfaceFactory::DrawCallback());
-  }
+  if (!surface_id_.is_null())
+    factory_.SubmitFrame(surface_id_, nullptr, SurfaceFactory::DrawCallback());
 }
 
 void SurfaceDisplayOutputSurface::ReturnResources(
     const ReturnedResourceArray& resources) {
   CompositorFrameAck ack;
   ack.resources = resources;
   if (client_)
     client_->ReclaimResources(&ack);
 }
 
 void SurfaceDisplayOutputSurface::SwapBuffersComplete(SurfaceDrawStatus drawn) {
   if (client_ && !display_client_->output_surface_lost())
     client_->DidSwapBuffersComplete();
 }
 
 }  // namespace cc