Added a level indicator to new mixer.

webrtc/modules/audio_mixer/new_audio_conference_mixer.h

 /*
  *  Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 41 matching lines @@
   // called from a single thread. The rate and channels arguments
   // specify the rate and number of channels of the mix result.
   virtual void Mix(int sample_rate,
                    size_t number_of_channels,
                    AudioFrame* audio_frame_for_mixing) = 0;
 
   // Returns true if the audio source is mixed anonymously.
   virtual bool AnonymousMixabilityStatus(
       const MixerAudioSource& audio_source) const = 0;
 
+  // Output level functions for VoEVolumeControl. Return value
+  // between 0 and 9 is returned by voe::AudioLevel.
+  virtual int GetOutputAudioLevel() = 0;
+
+  // Return value between 0 and 0x7fff is returned by voe::AudioLevel.
+  virtual int GetOutputAudioLevelFullRange() = 0;
+
  protected:
   NewAudioConferenceMixer() {}
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_MODULES_AUDIO_MIXER_NEW_AUDIO_CONFERENCE_MIXER_H_