Remove ViewHostMsg_UpdateIsDelayed

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 1242 matching lines @@
 void RenderWidget::AutoResizeCompositor()  {
   physical_backing_size_ = gfx::ToCeiledSize(gfx::ScaleSize(size_,
       device_scale_factor_));
   if (compositor_)
     compositor_->setViewportSize(size_, physical_backing_size_);
 }
 
 void RenderWidget::didActivateCompositor() {
   TRACE_EVENT0("gpu", "RenderWidget::didActivateCompositor");
 
-#if !defined(OS_MACOSX)
-  if (!is_accelerated_compositing_active_) {
-    // When not in accelerated compositing mode, in certain cases (e.g. waiting
-    // for a resize or if no backing store) the RenderWidgetHost is blocking the
-    // browser's UI thread for some time, waiting for an UpdateRect. If we are
-    // going to switch to accelerated compositing, the GPU process may need
-    // 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;
@@ skipping 946 matching lines @@
 
 void RenderWidget::RegisterSwappedOutChildFrame(RenderFrameImpl* frame) {
   swapped_out_frames_.AddObserver(frame);
 }
 
 void RenderWidget::UnregisterSwappedOutChildFrame(RenderFrameImpl* frame) {
   swapped_out_frames_.RemoveObserver(frame);
 }
 
 }  // namespace content