Use mus::MojoGpuMemoryBufferManager in mus::GpuService.

components/mus/gles2/mojo_buffer_backing.cc

-// Copyright 2014 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/mojo_buffer_backing.h"
-
-#include "base/logging.h"
-
-namespace mus {
-
-MojoBufferBacking::MojoBufferBacking(mojo::ScopedSharedBufferHandle handle,
-                                     void* memory,
-                                     size_t size)
-    : handle_(std::move(handle)), memory_(memory), size_(size) {}
-
-MojoBufferBacking::~MojoBufferBacking() {
-  mojo::UnmapBuffer(memory_);
-}
-
-// static
-std::unique_ptr<gpu::BufferBacking> MojoBufferBacking::Create(
-    mojo::ScopedSharedBufferHandle handle,
-    size_t size) {
-  void* memory = NULL;
-  MojoResult result = mojo::MapBuffer(handle.get(), 0, size, &memory,
-                                      MOJO_MAP_BUFFER_FLAG_NONE);
-  if (result != MOJO_RESULT_OK)
-    return std::unique_ptr<BufferBacking>();
-  DCHECK(memory);
-  return std::unique_ptr<BufferBacking>(
-      new MojoBufferBacking(std::move(handle), memory, size));
-}
-void* MojoBufferBacking::GetMemory() const {
-  return memory_;
-}
-size_t MojoBufferBacking::GetSize() const {
-  return size_;
-}
-
-}  // namespace mus