Changed the interface AudioMixer::RemoveSource to have a void return type.

webrtc/api/audio/audio_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 33 matching lines @@
     // A way for a mixer implementation to distinguish participants.
     virtual int Ssrc() const = 0;
 
     // A way for this source to say that GetAudioFrameWithInfo called
     // with this sample rate or higher will not cause quality loss.
     virtual int PreferredSampleRate() const = 0;
 
     virtual ~Source() {}
   };
 
-  // Returns true if adding/removing was successful. A source is never
-  // added twice and removal is never attempted if a source has not
-  // been successfully added to the mixer. Addition and removal can
-  // happen on different threads.
+  // Returns true if adding was successful. A source is never added
+  // twice. Addition and removal can happen on different threads.
   virtual bool AddSource(Source* audio_source) = 0;
-  virtual bool RemoveSource(Source* audio_source) = 0;
+
+  // Removal is never attempted if a source has not been successfully
+  // added to the mixer.
+  virtual void RemoveSource(Source* audio_source) = 0;
 
   // Performs mixing by asking registered audio sources for audio. The
   // mixed result is placed in the provided AudioFrame. This method
   // will only be called from a single thread. The channels argument
   // specifies the number of channels of the mix result. The mixer
   // should mix at a rate that doesn't cause quality loss of the
   // sources' audio. The mixing rate is one of the rates listed in
   // AudioProcessing::NativeRate. All fields in
   // |audio_frame_for_mixing| must be updated.
   virtual void Mix(size_t number_of_channels,
                    AudioFrame* audio_frame_for_mixing) = 0;
 
  protected:
   // Since the mixer is reference counted, the destructor may be
   // called from any thread.
   ~AudioMixer() override {}
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_AUDIO_AUDIO_MIXER_H_