Change SetOutputScaling to set a single level, not left/right levels.

talk/media/base/mediachannel.h

 /*
  * libjingle
  * Copyright 2004 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 1068 matching lines @@
   // Gets current energy levels for all incoming streams.
   virtual bool GetActiveStreams(AudioInfo::StreamList* actives) = 0;
   // Get the current energy level of the stream sent to the speaker.
   virtual int GetOutputLevel() = 0;
   // Get the time in milliseconds since last recorded keystroke, or negative.
   virtual int GetTimeSinceLastTyping() = 0;
   // Temporarily exposed field for tuning typing detect options.
   virtual void SetTypingDetectionParameters(int time_window,
     int cost_per_typing, int reporting_threshold, int penalty_decay,
     int type_event_delay) = 0;
-  // Set left and right scale for speaker output volume of the specified ssrc.
-  virtual bool SetOutputScaling(uint32_t ssrc, double left, double right) = 0;
+  // Set speaker output volume of the specified ssrc.
+  virtual bool SetOutputVolume(uint32_t ssrc, double volume) = 0;
   // Returns if the telephone-event has been negotiated.
   virtual bool CanInsertDtmf() { return false; }
   // Send and/or play a DTMF |event| according to the |flags|.
   // The DTMF out-of-band signal will be used on sending.
   // The |ssrc| should be either 0 or a valid send stream ssrc.
   // The valid value for the |event| are 0 to 15 which corresponding to
   // DTMF event 0-9, *, #, A-D.
   virtual bool InsertDtmf(uint32_t ssrc,
                           int event,
                           int duration,
@@ skipping 180 matching lines @@
   // Signal when the media channel is ready to send the stream. Arguments are:
   //     writable(bool)
   sigslot::signal1<bool> SignalReadyToSend;
   // Signal for notifying that the remote side has closed the DataChannel.
   sigslot::signal1<uint32_t> SignalStreamClosedRemotely;
 };
 
 }  // namespace cricket
 
 #endif  // TALK_MEDIA_BASE_MEDIACHANNEL_H_