mojo/gpu: use SharedBuffer instead of base::SharedMemory with hacks

mojo/services/gles2/command_buffer_type_conversions.h

 // 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.
 
 #ifndef MOJO_SERVICES_GLES2_COMMAND_BUFFER_TYPE_CONVERSIONS_H_
 #define MOJO_SERVICES_GLES2_COMMAND_BUFFER_TYPE_CONVERSIONS_H_
 
-#include "base/memory/shared_memory.h"
 #include "gpu/command_buffer/common/command_buffer.h"
 #include "mojo/public/cpp/bindings/type_converter.h"
 
 namespace mojo {
 
-class ShmHandle;
 class CommandBufferState;
 class Buffer;
 
 template <>
-class TypeConverter<ShmHandle, base::SharedMemoryHandle> {
- public:
-  static ShmHandle ConvertFrom(const base::SharedMemoryHandle& input,
-                               Buffer* buffer);
-  static base::SharedMemoryHandle ConvertTo(const ShmHandle& input);
-};
-
-template <>
 class TypeConverter<CommandBufferState, gpu::CommandBuffer::State> {
  public:
   static CommandBufferState ConvertFrom(const gpu::CommandBuffer::State& input,
                                         Buffer* buffer);
   static gpu::CommandBuffer::State ConvertTo(const CommandBufferState& input);
 };
 
 }  // namespace mojo
 
 #endif  // MOJO_SERVICES_GLES2_COMMAND_BUFFER_TYPE_CONVERSIONS_H_