Move AudioDevice and AudioInputDevice to media.

content/renderer/media/audio_device_thread.h

-// Copyright (c) 2012 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_RENDERER_MEDIA_AUDIO_DEVICE_THREAD_H_
-#define CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_THREAD_H_
-
-#include <vector>
-
-#include "base/basictypes.h"
-#include "base/memory/ref_counted.h"
-#include "base/shared_memory.h"
-#include "base/sync_socket.h"
-#include "base/synchronization/lock.h"
-#include "content/common/content_export.h"
-#include "media/audio/audio_parameters.h"
-
-class MessageLoop;
-
-// Data transfer between browser and render process uses a combination
-// of sync sockets and shared memory. To read from the socket and render
-// data, we use a worker thread, a.k.a. the AudioDeviceThread, which reads
-// data from the browser via the socket and fills the shared memory from the
-// audio thread via the AudioDeviceThread::Callback interface/class.
-// For more details see the documentation in audio_device.h.
-//
-// TODO(tommi): Multiple Audio[Input]Device instances should be able to share
-// the same thread instead of spinning one per instance.
-class CONTENT_EXPORT AudioDeviceThread {
- public:
-  // This is the callback interface/base class that Audio[Input]Device
-  // implements to render input/output data. The callback happens on the
-  // AudioDevice thread.
-  class Callback {
-   public:
-    Callback(const media::AudioParameters& audio_parameters,
-             base::SharedMemoryHandle memory,
-             int memory_length);
-    virtual ~Callback();
-
-    // One time initialization for the callback object on the audio thread.
-    void InitializeOnAudioThread();
-
-    // Derived implementations must call shared_memory_.Map appropriately
-    // before Process can be called.
-    virtual void MapSharedMemory() = 0;
-
-    // Called whenever we receive notifications about pending data.
-    virtual void Process(int pending_data) = 0;
-
-   protected:
-    // Protected so that derived classes can access directly.
-    // The variables are 'const' since values are calculated/set in the
-    // constructor and must never change.
-    const media::AudioParameters audio_parameters_;
-    const int samples_per_ms_;
-    const int bytes_per_ms_;
-
-    // Audio buffers that are allocated in InitializeOnAudioThread() based on
-    // info from audio_parameters_.
-    std::vector<float*> audio_data_;
-    base::SharedMemory shared_memory_;
-    const int memory_length_;
-
-   private:
-    DISALLOW_COPY_AND_ASSIGN(Callback);
-  };
-
-  AudioDeviceThread();
-  ~AudioDeviceThread();
-
-  // Starts the audio thread. The thread must not already be running.
-  void Start(AudioDeviceThread::Callback* callback,
-             base::SyncSocket::Handle socket,
-             const char* thread_name);
-
-  // This tells the audio thread to stop and clean up the data.
-  // The method can stop the thread synchronously or asynchronously.
-  // In the latter case, the thread will still be running after Stop()
-  // returns, but the callback pointer is cleared so no further callbacks will
-  // be made (IOW after Stop() returns, it is safe to delete the callback).
-  // The |loop_for_join| parameter is required for asynchronous operation
-  // in order to join the worker thread and close the thread handle later via a
-  // posted task.
-  // If set to NULL, function will wait for the thread to exit before returning.
-  void Stop(MessageLoop* loop_for_join);
-
-  // Returns true if the thread is stopped or stopping.
-  bool IsStopped();
-
- private:
-  // Our own private SimpleThread override.  We implement this in a
-  // private class so that we get the following benefits:
-  // 1) AudioDeviceThread doesn't expose SimpleThread methods.
-  //    I.e. the caller can't call Start()/Stop() - which would be bad.
-  // 2) We override ThreadMain to add additional on-thread initialization
-  //    while still synchronized with SimpleThread::Start() to provide
-  //    reliable initialization.
-  class Thread;
-
-  base::Lock thread_lock_;
-  scoped_refptr<AudioDeviceThread::Thread> thread_;
-
-  DISALLOW_COPY_AND_ASSIGN(AudioDeviceThread);
-};
-
-#endif  // CONTENT_RENDERER_MEDIA_AUDIO_DEVICE_THREAD_H_