Revert of Rewrote UpdateToMix in the audio mixer.

webrtc/modules/audio_mixer/include/audio_mixer_defines.h

Index: webrtc/modules/audio_mixer/include/audio_mixer_defines.h
diff --git a/webrtc/modules/audio_mixer/include/audio_mixer_defines.h b/webrtc/modules/audio_mixer/include/audio_mixer_defines.h
index 253e8f788c0dbe20b0b7b7a1f671adbf62ca08f1..a1574ac2405f9ebe148a9b0ae45bcafcfd22e938 100644
--- a/webrtc/modules/audio_mixer/include/audio_mixer_defines.h
+++ b/webrtc/modules/audio_mixer/include/audio_mixer_defines.h
@@ -29,7 +29,7 @@
     kError    // audio_frame will not be used.
   };
 
-  struct AudioFrameWithMuted {
+  struct AudioFrameWithInfo {
     AudioFrame* audio_frame;
     AudioFrameInfo audio_frame_info;
   };
@@ -40,8 +40,8 @@
   // different calls. The pointer must stay valid until the next
   // mixing call or until this audio source is disconnected from the
   // mixer.
-  virtual AudioFrameWithMuted GetAudioFrameWithMuted(int32_t id,
-                                                     int sample_rate_hz) = 0;
+  virtual AudioFrameWithInfo GetAudioFrameWithMuted(int32_t id,
+                                                    int sample_rate_hz) = 0;
 
   // Returns true if the participant was mixed this mix iteration.
   bool IsMixed() const;