Added a level indicator to new mixer.

webrtc/modules/audio_mixer/new_audio_conference_mixer.h

Index: webrtc/modules/audio_mixer/new_audio_conference_mixer.h
diff --git a/webrtc/modules/audio_mixer/new_audio_conference_mixer.h b/webrtc/modules/audio_mixer/new_audio_conference_mixer.h
index 561cf88604f58cf51ee4352f10e8e7df0bd6f1e2..52d79ee75bb9a57c014f4fe1253c39b8308435dc 100644
--- a/webrtc/modules/audio_mixer/new_audio_conference_mixer.h
+++ b/webrtc/modules/audio_mixer/new_audio_conference_mixer.h
@@ -59,6 +59,13 @@ class NewAudioConferenceMixer {
   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() {}
 };