Add an ALSA output to the motown audio server.

services/media/audio/audio_output_manager.h

 // Copyright 2015 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 SERVICES_MEDIA_AUDIO_AUDIO_OUTPUT_MANAGER_H_
 #define SERVICES_MEDIA_AUDIO_AUDIO_OUTPUT_MANAGER_H_
 
 #include <set>
 
 #include "base/synchronization/lock.h"
@@ skipping 39 matching lines @@
 
   // Schedule a closure to run on our encapsulating server's main message loop.
   void ScheduleMessageLoopTask(const tracked_objects::Location& from_here,
                                const base::Closure& task);
 
   // Shutdown the specified audio output and remove it from the set of active
   // outputs.
   void ShutdownOutput(AudioOutputPtr output);
 
  private:
+  void CreateAlsaOutputs();
+
   // TODO(johngro): A SequencedWorkerPool currently seems to be as close to what
   // we want which we can currently get using the chrome/mojo framework.  Things
   // which are missing and will eventually need to be addressed include...
   //
   // 1) Threads are created on the fly, as needed.  We really want to be able to
   //    spin up the proper number of threads at pool creation time.  Audio
   //    mixing is very timing sensitive...  If we are in a situation where we
   //    have not hit the max number of threads in the pool, and we need to spin
   //    up a thread in order to mix, we *really* do not want to have to wait to
   //    create the thread at the OS level before we can mix some audio.  The
@@ skipping 30 matching lines @@
   // Contents of the output set must only be manipulated on the main message
   // loop thread, so no synchronization should be needed.
   AudioOutputSet outputs_;
 };
 
 }  // namespace audio
 }  // namespace media
 }  // namespace mojo
 
 #endif  // SERVICES_MEDIA_AUDIO_AUDIO_OUTPUT_MANAGER_H_