ozone: Implement zero/one-copy texture for Ozone GBM.

content/common/gpu/client/gpu_memory_buffer_impl_ozone_gbm.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 CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_OZONE_GBM_H_
+#define CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_OZONE_GBM_H_
+
+#include "content/common/gpu/client/gpu_memory_buffer_impl_ozone_native_buffer.h"
+
+struct gbm_bo;
+
+namespace content {
+
+// Implementation of GPU memory buffer based on Ozone GBM.
+class GpuMemoryBufferImplOzoneGbm

[reveman, 2015/05/11 16:40:56]

We shouldn't have multiple Ozone abstractions for GMBs. As long as
OzoneNativeBuffer exists, all ozone GMB support should be hidden behind that
interface.

[dshwang, 2015/05/11 17:11:53]

it's directly related to spang's concern also.
GpuMemoryBufferImpl class is defined in content/common/gpu/client, so I could
not move this implementation to ui/ozone/platform due to cyclic dependency.
To hide this in ui/ozone/, GpuMemoryBufferImpl should move to another module
which ui/ozone can depend on.
I think it's better that GpuMemoryBuffer in ui/gfx should be merged with
GpuMemoryBufferImpl, rather than moving GpuMemoryBufferImpl to ui/gfx. I'll do
it in another CL.
WDYT?

[dshwang, 2015/05/14 12:25:46]

I understand. I merge this into OzoneNativeBuffer.

+    : public GpuMemoryBufferImplOzoneNativeBuffer {
+ public:
+  static scoped_ptr<GpuMemoryBufferImpl> CreateFromHandle(
+      const gfx::GpuMemoryBufferHandle& handle,
+      const gfx::Size& size,
+      Format format,
+      const DestructionCallback& callback);
+  ~GpuMemoryBufferImplOzoneGbm() override;
+
+  // Overridden from gfx::GpuMemoryBuffer:
+  bool Map(void** data) override;
+  void Unmap() override;
+  void GetStride(int* stride) const override;
+  gfx::GpuMemoryBufferHandle GetHandle() const override;
+
+ private:
+  GpuMemoryBufferImplOzoneGbm(gfx::GpuMemoryBufferId id,
+                              const gfx::Size& size,
+                              Format format,
+                              const DestructionCallback& callback);
+
+  bool Initialize(const gfx::GpuMemoryBufferHandle& handle);
+
+  uint32_t vgem_bo_handle_;
+  base::ScopedFD dma_buf_;
+  size_t stride_;
+  void* mmap_ptr_;
+
+  DISALLOW_COPY_AND_ASSIGN(GpuMemoryBufferImplOzoneGbm);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_GPU_CLIENT_GPU_MEMORY_BUFFER_IMPL_OZONE_GBM_H_