gpu: Refactor memory buffer handling code out of content.

services/ui/public/cpp/mojo_gpu_memory_buffer_manager.h

 // 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.
 
 #ifndef SERVICES_UI_PUBLIC_CPP_MOJO_GPU_MEMORY_BUFFER_MANAGER_H_
 #define SERVICES_UI_PUBLIC_CPP_MOJO_GPU_MEMORY_BUFFER_MANAGER_H_
 
 #include <memory>
 
 #include "base/macros.h"
+#include "base/single_thread_task_runner.h"
 #include "gpu/command_buffer/client/gpu_memory_buffer_manager.h"
+#include "services/ui/public/interfaces/gpu_service.mojom.h"
 
 namespace ui {
 
 class MojoGpuMemoryBufferManager : public gpu::GpuMemoryBufferManager {
  public:
-  MojoGpuMemoryBufferManager();
+  explicit MojoGpuMemoryBufferManager(mojom::GpuService* gpu_service);
   ~MojoGpuMemoryBufferManager() override;
 
   // Overridden from gpu::GpuMemoryBufferManager:
   std::unique_ptr<gfx::GpuMemoryBuffer> AllocateGpuMemoryBuffer(
       const gfx::Size& size,
       gfx::BufferFormat format,
       gfx::BufferUsage usage,
       gpu::SurfaceHandle surface_handle) override;
   std::unique_ptr<gfx::GpuMemoryBuffer> CreateGpuMemoryBufferFromHandle(
       const gfx::GpuMemoryBufferHandle& handle,
       const gfx::Size& size,
       gfx::BufferFormat format) override;
   gfx::GpuMemoryBuffer* GpuMemoryBufferFromClientBuffer(
       ClientBuffer buffer) override;
   void SetDestructionSyncToken(gfx::GpuMemoryBuffer* buffer,
                                const gpu::SyncToken& sync_token) override;
 
  private:
+  void EnsureGpuServiceConnection();
+
+  void AllocateGpuMemoryBufferOnMain(gfx::GpuMemoryBufferId id,
+                                     const gfx::Size& size,
+                                     gfx::BufferFormat format,
+                                     gfx::BufferUsage usage,
+                                     gfx::GpuMemoryBufferHandle* handle,
+                                     base::WaitableEvent* event);
+
+  scoped_refptr<base::SingleThreadTaskRunner> main_task_runner_;
+  mojom::GpuService* gpu_service_;
+
   DISALLOW_COPY_AND_ASSIGN(MojoGpuMemoryBufferManager);
 };
 
 }  // namespace ui
 
 #endif  // SERVICES_UI_PUBLIC_CPP_MOJO_GPU_MEMORY_BUFFER_MANAGER_H_