Switch audio synchronization from sleep() based to select() based.

media/audio/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 MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_
 #define MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_
 
 #include "base/basictypes.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/shared_memory.h"
 #include "base/sync_socket.h"
 #include "base/synchronization/lock.h"
 #include "media/audio/audio_parameters.h"
-#include "media/audio/shared_memory_util.h"
 #include "media/base/media_export.h"
 
 namespace base {
 class MessageLoop;
 }
 
 namespace media {
 class AudioBus;
 
 // Data transfer between browser and render process uses a combination
@@ skipping 41 matching lines @@
     const int total_segments_;
     int segment_length_;
 
    private:
     DISALLOW_COPY_AND_ASSIGN(Callback);
   };
 
   AudioDeviceThread();
   ~AudioDeviceThread();
 
-  // Starts the audio thread. The thread must not already be running.
+  // Starts the audio thread. The thread must not already be running.  If
+  // |sychronized_buffers| is set, the browser expects to be notified via the
+  // |socket| every time AudioDeviceThread::Process() completes.
   void Start(AudioDeviceThread::Callback* callback,
              base::SyncSocket::Handle socket,
-             const char* thread_name);
+             const char* thread_name,
+             bool synchronized_buffers);
 
   // 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.
@@ skipping 14 matching lines @@
 
   base::Lock thread_lock_;
   scoped_refptr<AudioDeviceThread::Thread> thread_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioDeviceThread);
 };
 
 }  // namespace media.
 
 #endif  // MEDIA_AUDIO_AUDIO_DEVICE_THREAD_H_