Add an ALSA output to the motown audio server.

services/media/audio/audio_output_manager.h

Index: services/media/audio/audio_output_manager.h
diff --git a/services/media/audio/audio_output_manager.h b/services/media/audio/audio_output_manager.h
index 2599ee57ef01b351ce0178e6ca8f074d8f2209d2..16693140a04199f34a19bd64e158e7b488848813 100644
--- a/services/media/audio/audio_output_manager.h
+++ b/services/media/audio/audio_output_manager.h
@@ -57,6 +57,8 @@ class AudioOutputManager {
   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...