Extract nested and private classes from VideoCaptureBufferPool

content/browser/renderer_host/media/shared_memory_buffer_tracker.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_TRACKER_H_
+#define CONTENT_BROWSER_RENDERER_HOST_MEDIA_SHARED_MEMORY_BUFFER_TRACKER_H_
+
+#include "content/browser/renderer_host/media/video_capture_buffer_tracker.h"
+
+namespace content {
+
+// Tracker specifics for SharedMemory.
+class SharedMemoryBufferTracker final : public VideoCaptureBufferTracker {
+ public:
+  SharedMemoryBufferTracker();
+
+  bool Init(const gfx::Size& dimensions,
+            media::VideoPixelFormat format,
+            media::VideoPixelStorage storage_type,
+            base::Lock* lock) override;
+
+  std::unique_ptr<VideoCaptureBufferHandle> GetBufferHandle() override;
+  bool ShareToProcess(base::ProcessHandle process_handle,
+                      base::SharedMemoryHandle* new_handle) override;
+  bool ShareToProcess2(int plane,
+                       base::ProcessHandle process_handle,
+                       gfx::GpuMemoryBufferHandle* new_handle) override;
+
+ private:
+  friend class SharedMemoryBufferHandle;
+
+  // The memory created to be shared with renderer processes.
+  base::SharedMemory shared_memory_;
+  size_t mapped_size_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_SHARED_MEMORY_BUFFER_TRACKER_H_