Add IPC allowing GPU process to tell browser process to temporarily drop a front buffer.

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.
 
 #if defined(ENABLE_GPU)
 
 #include "content/common/gpu/image_transport_surface.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 154 matching lines @@
   stub_->SetSwapInterval();
 }
 
 bool ImageTransportHelper::MakeCurrent() {
   gpu::gles2::GLES2Decoder* decoder = Decoder();
   if (!decoder)
     return false;
   return decoder->MakeCurrent();
 }
 
+void ImageTransportHelper::Suspend() {
+  manager_->Send(new GpuHostMsg_AcceleratedSurfaceSuspend(stub_->surface_id()));
+}
+
 gpu::GpuScheduler* ImageTransportHelper::Scheduler() {
   if (!stub_.get())
     return NULL;
   return stub_->scheduler();
 }
 
 gpu::gles2::GLES2Decoder* ImageTransportHelper::Decoder() {
   if (!stub_.get())
     return NULL;
   return stub_->decoder();
@@ skipping 75 matching lines @@
 }
 
 void PassThroughImageTransportSurface::OnResize(gfx::Size size) {
   new_size_ = size;
 
   helper_->SendResizeView(size);
   helper_->SetScheduled(false);
 }
 
 #endif  // defined(ENABLE_GPU)