Let default device in PulseAudio be the system default device

media/audio/pulse/pulse_util.h

Index: media/audio/pulse/pulse_util.h
diff --git a/media/audio/pulse/pulse_util.h b/media/audio/pulse/pulse_util.h
index b8e5cdcda4c606eaef98770e1507bbff99522855..455929e81941a9ee9a35ec6789e8cad1aca28c9a 100644
--- a/media/audio/pulse/pulse_util.h
+++ b/media/audio/pulse/pulse_util.h
@@ -48,11 +48,12 @@ void WaitForOperationCompletion(pa_threaded_mainloop* mainloop,
 int GetHardwareLatencyInBytes(pa_stream* stream,
                               int sample_rate,
                               int bytes_per_frame);
-
 // Create a recording stream for the threaded mainloop, return true if success,
 // otherwise false. |mainloop| and |context| have to be from a valid Pulse
 // threaded mainloop and the handle of the created stream will be returned by
 // |stream|.
+// TODO(grunell): Move this function to PulseAudioInputStream class since it's
+// only used there.
 bool CreateInputStream(pa_threaded_mainloop* mainloop,
                        pa_context* context,
                        pa_stream** stream,
@@ -65,8 +66,10 @@ bool CreateInputStream(pa_threaded_mainloop* mainloop,
 // otherwise false. This function will create a new Pulse threaded mainloop,
 // and the handles of the mainloop, context and stream will be returned by
 // |mainloop|, |context| and |stream|.
-bool CreateOutputStream(pa_threaded_mainloop** mainloop,
-                        pa_context** context,
+// TODO(grunell): Move this function to PulseAudioOutputStream class since it's
+// only used there.
+bool CreateOutputStream(pa_threaded_mainloop* mainloop,
+                        pa_context* context,
                         pa_stream** stream,
                         const AudioParameters& params,
                         const std::string& device_id,