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

components/mus/gles2/command_buffer_local.cc

 // Copyright 2015 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 "components/mus/gles2/command_buffer_local.h"
 
 #include "base/bind.h"
 #include "base/memory/shared_memory.h"
 #include "components/mus/gles2/command_buffer_local_client.h"
 #include "components/mus/gles2/gpu_memory_tracker.h"
@@ skipping 148 matching lines @@
 }
 
 int32_t CommandBufferLocal::CreateGpuMemoryBufferImage(size_t width,
                                                        size_t height,
                                                        unsigned internalformat,
                                                        unsigned usage) {
   DCHECK_EQ(usage, static_cast<unsigned>(GL_READ_WRITE_CHROMIUM));
   scoped_ptr<gfx::GpuMemoryBuffer> buffer(MojoGpuMemoryBufferImpl::Create(
       gfx::Size(static_cast<int>(width), static_cast<int>(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_t CommandBufferLocal::InsertSyncPoint() {
   return 0;
 }
 
 uint32_t CommandBufferLocal::InsertFutureSyncPoint() {
@@ skipping 148 matching lines @@
 void CommandBufferLocal::OnContextLost(uint32_t reason) {
   if (client_)
     client_->DidLoseContext();
 }
 
 void CommandBufferLocal::OnSyncPointRetired() {
   scheduler_->SetScheduled(true);
 }
 
 }  // namespace mus