gpu: Add IOSurface backed GpuMemoryBuffer implementation.

content/common/gpu/client/gpu_memory_buffer_impl_shm.h

+// 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.
+
+#ifndef CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_SHM_H_
+#define CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_SHM_H_
+
+#include "content/common/gpu/client/gpu_memory_buffer_impl.h"
+
+namespace content {
+
+// Provides implementation of a GPU memory buffer based
+// on a shared memory handle.
+class GpuMemoryBufferImplShm : public GpuMemoryBufferImpl {
+ public:
+  GpuMemoryBufferImplShm(gfx::Size size, unsigned internalformat);
+  virtual ~GpuMemoryBufferImplShm();
+
+  bool Initialize(gfx::GpuMemoryBufferHandle handle);
+  bool InitializeFromSharedMemory(
+      scoped_ptr<base::SharedMemory> shared_memory);
+
+  // Overridden from gfx::GpuMemoryBuffer:
+  virtual void Map(AccessMode mode, void** vaddr) OVERRIDE;
+  virtual void Unmap() OVERRIDE;
+  virtual gfx::GpuMemoryBufferHandle GetHandle() const OVERRIDE;
+
+ private:
+  scoped_ptr<base::SharedMemory> shared_memory_;
+
+  DISALLOW_COPY_AND_ASSIGN(GpuMemoryBufferImplShm);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_SHM_H_