Revert of Make SingleThreadProxy a SchedulerClient

content/renderer/render_widget.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/renderer/render_widget.h"
 
 #include "base/auto_reset.h"
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 1166 matching lines @@
 }
 
 void RenderWidget::suppressCompositorScheduling(bool enable) {
   if (compositor_)
     compositor_->SetSuppressScheduleComposite(enable);
 }
 
 void RenderWidget::willBeginCompositorFrame() {
   TRACE_EVENT0("gpu", "RenderWidget::willBeginCompositorFrame");
 
+  DCHECK(RenderThreadImpl::current()->compositor_message_loop_proxy().get());
+
   // The following two can result in further layout and possibly
   // enable GPU acceleration so they need to be called before any painting
   // is done.
   UpdateTextInputState(NO_SHOW_IME, FROM_NON_IME);
   UpdateSelectionBounds();
 }
 
 void RenderWidget::didBecomeReadyForAdditionalInput() {
   TRACE_EVENT0("renderer", "RenderWidget::didBecomeReadyForAdditionalInput");
   FlushPendingInputEventAck();
@@ skipping 860 matching lines @@
 void RenderWidget::RegisterVideoHoleFrame(RenderFrameImpl* frame) {
   video_hole_frames_.AddObserver(frame);
 }
 
 void RenderWidget::UnregisterVideoHoleFrame(RenderFrameImpl* frame) {
   video_hole_frames_.RemoveObserver(frame);
 }
 #endif  // defined(VIDEO_HOLE)
 
 }  // namespace content