Avoid sending empty OnRepaint msgs and propagate window damage correctly

content/common/gpu/image_transport_surface.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/common/gpu/image_transport_surface.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/debug/trace_event.h"
@@ skipping 304 matching lines @@
   if (did_unschedule_) {
     did_unschedule_ = false;
     helper_->SetScheduled(true);
   }
 }
 
 void PassThroughImageTransportSurface::OnResizeViewACK() {
   DCHECK(transport_);
   Resize(new_size_);
 
+  TRACE_EVENT_ASYNC_END0("gpu", "OnResize", this);
   helper_->SetScheduled(true);
 }
 
 void PassThroughImageTransportSurface::OnResize(gfx::Size size) {
   new_size_ = size;
 
   if (transport_) {
     helper_->SendResizeView(size);
     helper_->SetScheduled(false);
+    TRACE_EVENT_ASYNC_BEGIN2("gpu", "OnResize", this,
+                             "width", size.width(), "height", size.height());
   } else {
     Resize(new_size_);
   }
 }
 
 gfx::Size PassThroughImageTransportSurface::GetSize() {
   return GLSurfaceAdapter::GetSize();
 }
 
 PassThroughImageTransportSurface::~PassThroughImageTransportSurface() {}
 
 void PassThroughImageTransportSurface::SendVSyncUpdateIfAvailable() {
   gfx::VSyncProvider* vsync_provider = GetVSyncProvider();
   if (vsync_provider) {
     vsync_provider->GetVSyncParameters(
       base::Bind(&ImageTransportHelper::SendUpdateVSyncParameters,
                  helper_->AsWeakPtr()));
   }
 }
 
 }  // namespace content