Extract nested and private classes from VideoCaptureBufferPool

content/browser/renderer_host/media/shared_memory_buffer_handle.h

+// Copyright 2016 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_BROWSER_RENDERER_HOST_MEDIA_SHARED_MEMORY_BUFFER_HANDLE_H_
+#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_SHARED_MEMORY_BUFFER_HANDLE_H_
+
+#include "content/browser/renderer_host/media/video_capture_buffer_handle.h"
+
+namespace content {
+
+class SharedMemoryBufferTracker;
+
+// A simple proxy that implements the BufferHandle interface, providing
+// accessors to SharedMemTracker's memory and properties.
+class SharedMemoryBufferHandle : public VideoCaptureBufferHandle {
+ public:
+  // |tracker| must outlive SimpleBufferHandle. This is ensured since a
+  // tracker is pinned until ownership of this SimpleBufferHandle is returned
+  // to VideoCaptureBufferPool.
+  explicit SharedMemoryBufferHandle(SharedMemoryBufferTracker* tracker);
+  ~SharedMemoryBufferHandle() override;
+
+  gfx::Size dimensions() const override;
+  size_t mapped_size() const override;
+  void* data(int plane) override;
+  ClientBuffer AsClientBuffer(int plane) override;
+#if defined(OS_POSIX) && !defined(OS_MACOSX)
+  base::FileDescriptor AsPlatformFile() override;
+#endif
+
+ private:
+  SharedMemoryBufferTracker* const tracker_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_SHARED_MEMORY_BUFFER_HANDLE_H_