ui: Revert gfx::BufferUsage::SCANOUT to gfx::BufferUsage::GPU_READ_WRITE change.

content/common/gpu/client/command_buffer_proxy_impl.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/client/command_buffer_proxy_impl.h"
 
 #include <vector>
 
 #include "base/callback.h"
 #include "base/logging.h"
@@ skipping 444 matching lines @@
 int32_t CommandBufferProxyImpl::CreateGpuMemoryBufferImage(
     size_t width,
     size_t height,
     unsigned internalformat,
     unsigned usage) {
   CheckLock();
   scoped_ptr<gfx::GpuMemoryBuffer> buffer(
       channel_->gpu_memory_buffer_manager()->AllocateGpuMemoryBuffer(
           gfx::Size(width, height),
           gpu::ImageFactory::DefaultBufferFormatForImageFormat(internalformat),
-          gfx::BufferUsage::GPU_READ_WRITE));
+          gfx::BufferUsage::SCANOUT));
   if (!buffer)
     return -1;
 
   return CreateImage(buffer->AsClientBuffer(), width, height, internalformat);
 }
 
 uint32 CommandBufferProxyImpl::CreateStreamTexture(uint32 texture_id) {
   CheckLock();
   if (last_state_.error != gpu::error::kNoError)
     return 0;
@@ skipping 262 matching lines @@
   }
 }
 
 void CommandBufferProxyImpl::OnUpdateVSyncParameters(base::TimeTicks timebase,
                                                      base::TimeDelta interval) {
   if (!update_vsync_parameters_completion_callback_.is_null())
     update_vsync_parameters_completion_callback_.Run(timebase, interval);
 }
 
 }  // namespace content