Remove code only used by Mac single threaded compositing.

content/test/test_render_view_host.cc

 // Copyright (c) 2012 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 "content/test/test_render_view_host.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "content/browser/dom_storage/dom_storage_context_wrapper.h"
 #include "content/browser/dom_storage/session_storage_namespace_impl.h"
 #include "content/browser/site_instance_impl.h"
@@ skipping 138 matching lines @@
 void TestRenderWidgetHostView::AcceleratedSurfaceSuspend() {
 }
 
 bool TestRenderWidgetHostView::HasAcceleratedSurface(
       const gfx::Size& desired_size) {
   return false;
 }
 
 #if defined(OS_MACOSX)
 
-void TestRenderWidgetHostView::AboutToWaitForBackingStoreMsg() {
-}
-
 void TestRenderWidgetHostView::SetActive(bool active) {
   // <viettrungluu@gmail.com>: Do I need to do anything here?
 }
 
 bool TestRenderWidgetHostView::SupportsSpeech() const {
   return false;
 }
 
 void TestRenderWidgetHostView::SpeakSelection() {
 }
@@ skipping 266 matching lines @@
 
 TestRenderFrameHost* RenderViewHostImplTestHarness::main_test_rfh() {
   return static_cast<TestRenderFrameHost*>(main_rfh());
 }
 
 TestWebContents* RenderViewHostImplTestHarness::contents() {
   return static_cast<TestWebContents*>(web_contents());
 }
 
 }  // namespace content