Remove browser-side tracking of accelerated compositing

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/bind.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
 #include "base/debug/trace_event_synthetic_delay.h"
@@ skipping 1258 matching lines @@
     // round-trips to the browser's UI thread before finishing the frame,
     // causing deadlocks if we delay the UpdateRect until we receive the
     // OnSwapBuffersComplete.  So send a dummy message that will unblock the
     // browser's UI thread. This is not necessary on Mac, because SwapBuffers
     // now unblocks GetBackingStore on Mac.
     Send(new ViewHostMsg_UpdateIsDelayed(routing_id_));
   }
 #endif
 
   is_accelerated_compositing_active_ = true;
-  Send(new ViewHostMsg_DidActivateAcceleratedCompositing(
-      routing_id_, is_accelerated_compositing_active_));
   webwidget_->enterForceCompositingMode(true);
 }
 
 void RenderWidget::didDeactivateCompositor() {
   TRACE_EVENT0("gpu", "RenderWidget::didDeactivateCompositor");
 
   is_accelerated_compositing_active_ = false;
-  Send(new ViewHostMsg_DidActivateAcceleratedCompositing(
-      routing_id_, is_accelerated_compositing_active_));
 }
 
 void RenderWidget::initializeLayerTreeView() {
   compositor_ = RenderWidgetCompositor::Create(
       this, is_threaded_compositing_enabled_);
   compositor_->setViewportSize(size_, physical_backing_size_);
   if (init_complete_)
     StartCompositor();
 }
 
@@ skipping 934 matching lines @@
 
 void RenderWidget::RegisterSwappedOutChildFrame(RenderFrameImpl* frame) {
   swapped_out_frames_.AddObserver(frame);
 }
 
 void RenderWidget::UnregisterSwappedOutChildFrame(RenderFrameImpl* frame) {
   swapped_out_frames_.RemoveObserver(frame);
 }
 
 }  // namespace content