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diff --git a/chromium/ppapi/shared_impl/media_stream_buffer_manager.h b/chromium/ppapi/shared_impl/media_stream_buffer_manager.h
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+++ b/chromium/ppapi/shared_impl/media_stream_buffer_manager.h
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+// Copyright 2014 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 PPAPI_SHARED_IMPL_MEDIA_STREAM_BUFFER_MANAGER_H_
+#define PPAPI_SHARED_IMPL_MEDIA_STREAM_BUFFER_MANAGER_H_
+
+#include <deque>
+#include <vector>
+
+#include "base/compiler_specific.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/shared_memory.h"
+#include "ppapi/shared_impl/ppapi_shared_export.h"
+
+namespace ppapi {
+
+union MediaStreamBuffer;
+
+// This class is used by both read side and write side of a MediaStreamTrack to
+// maintain a queue of buffers for reading or writing.
+//
+// An example:
+//  1. The writer calls the writer's |buffer_manager_.Dequeue()| to get a free
+//     buffer.
+//  2. The writer fills data into the buffer.
+//  3. The writer sends the buffer index to the reader via an IPC message.
+//  4. The reader receives the buffer index and calls the reader's
+//     |buffer_buffer.Enqueue()| to put the buffer into the read's queue.
+//  5. The reader calls reader's |buffer_buffer_.Dequeue()| to get a received
+//     buffer.
+//  6. When the buffer from the step 5 is consumed, the reader sends the buffer
+//     index back to writer via an IPC message.
+//  7. The writer receives the buffer index and puts it back to the writer's
+//     free buffer queue by calling the writer's |buffer_manager_.Enqueue()|.
+//  8. Go back to step 1.
+class PPAPI_SHARED_EXPORT MediaStreamBufferManager {
+ public:
+  class PPAPI_SHARED_EXPORT Delegate {
+   public:
+    virtual ~Delegate();
+    // It is called when a new buffer is enqueued.
+    virtual void OnNewBufferEnqueued();
+  };
+
+  // MediaStreamBufferManager doesn't own |delegate|, the caller should keep
+  // it alive during the MediaStreamBufferManager's lifecycle.
+  explicit MediaStreamBufferManager(Delegate* delegate);
+
+  ~MediaStreamBufferManager();
+
+  int32_t number_of_buffers() const { return number_of_buffers_; }
+
+  int32_t buffer_size() const { return buffer_size_; }
+
+  // Initializes shared memory for buffers transmission.
+  bool SetBuffers(int32_t number_of_buffers,
+                  int32_t buffer_size,
+                  scoped_ptr<base::SharedMemory> shm,
+                  bool enqueue_all_buffers);
+
+  // Dequeues a buffer from |buffer_queue_|.
+  int32_t DequeueBuffer();
+
+  // Dequeues all the buffers from |buffer_queue_|.
+  std::vector<int32_t> DequeueBuffers();
+
+  // Puts a buffer into |buffer_queue_|.
+  void EnqueueBuffer(int32_t index);
+
+  // Gets the buffer address for the given buffer index.
+  MediaStreamBuffer* GetBufferPointer(int32_t index);
+
+ private:
+  Delegate* delegate_;
+
+  // A queue of buffer indices.
+  std::deque<int32_t> buffer_queue_;
+
+  // A vector of buffer pointers. It is used for index to pointer converting.
+  std::vector<MediaStreamBuffer*> buffers_;
+
+  // The buffer size in bytes.
+  int32_t buffer_size_;
+
+  // The number of buffers in the shared memory.
+  int32_t number_of_buffers_;
+
+  // A memory block shared between renderer process and plugin process.
+  scoped_ptr<base::SharedMemory> shm_;
+
+  DISALLOW_COPY_AND_ASSIGN(MediaStreamBufferManager);
+};
+
+}  // namespace ppapi
+
+#endif  // PPAPI_SHAERD_IMPL_MEDIA_STREAM_BUFFER_MANAGER_H_