Don't allow processing of a command buffer to overlap with a previous swap.

content/common/gpu/image_transport_surface_win.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/command_line.h"
@@ skipping 181 matching lines @@
 void PbufferImageTransportSurface::SendBuffersSwapped() {
   GpuHostMsg_AcceleratedSurfaceBuffersSwapped_Params params;
   params.surface_handle = reinterpret_cast<int64>(GetShareHandle());
   CHECK(params.surface_handle);
 
   params.size = GetSize();
   helper_->SendAcceleratedSurfaceBuffersSwapped(params);
 
   DCHECK(!is_swap_buffers_pending_);
   is_swap_buffers_pending_ = true;
+
+  // Pause all processing of this command buffer.

[jbates, 2012/07/27 21:39:57]

better put the bug number here just in case it sits for a while

+  DeferDraws();
 }
 
 void PbufferImageTransportSurface::OnBufferPresented(uint32 sync_point) {
   is_swap_buffers_pending_ = false;
   if (did_unschedule_) {
     did_unschedule_ = false;
     helper_->SetScheduled(true);
   }
 }
 
@@ skipping 47 matching lines @@
                                                    handle.transport);
   }
 
   if (surface->Initialize())
     return surface;
   else
     return NULL;
 }
 
 #endif  // ENABLE_GPU