Implement native GMB backbuffers in the GLES2 Command Decoder.

components/mus/gles2/command_buffer_driver.cc

 // Copyright 2013 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_driver.h"
 
 #include <stddef.h>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 112 matching lines @@
     return false;
 
   if (!context_->MakeCurrent(surface_.get()))
     return false;
 
   // TODO(piman): ShaderTranslatorCache is currently per-ContextGroup but
   // only needs to be per-thread.
   const bool bind_generates_resource = attrib_helper.bind_generates_resource;
   scoped_refptr<gpu::gles2::FeatureInfo> feature_info =
       new gpu::gles2::FeatureInfo(gpu_state_->gpu_driver_bug_workarounds());
+  // TODO(erikchen): The ContextGroup needs a reference to the
+  // GpuMemoryBufferManager.
   scoped_refptr<gpu::gles2::ContextGroup> context_group =
       new gpu::gles2::ContextGroup(
           gpu_state_->gpu_preferences(), gpu_state_->mailbox_manager(),
           new GpuMemoryTracker,
           new gpu::gles2::ShaderTranslatorCache(gpu_state_->gpu_preferences()),
           new gpu::gles2::FramebufferCompletenessCache, feature_info,
-          bind_generates_resource);
+          bind_generates_resource, nullptr);
 
   command_buffer_.reset(
       new gpu::CommandBufferService(context_group->transfer_buffer_manager()));
 
   decoder_.reset(::gpu::gles2::GLES2Decoder::Create(context_group.get()));
   executor_.reset(new gpu::CommandExecutor(command_buffer_.get(),
                                            decoder_.get(), decoder_.get()));
   sync_point_order_data_ = gpu::SyncPointOrderData::Create();
   sync_point_client_ = gpu_state_->sync_point_manager()->CreateSyncPointClient(
       sync_point_order_data_, GetNamespaceID(), command_buffer_id_);
@@ skipping 406 matching lines @@
 }
 
 void CommandBufferDriver::OnGpuCompletedSwapBuffers(gfx::SwapResult result) {
   DCHECK(CalledOnValidThread());
   if (client_) {
     client_->OnGpuCompletedSwapBuffers(result);
   }
 }
 
 }  // namespace mus