Style changes in Audio Mixer

webrtc/modules/audio_mixer/audio_mixer.h

Index: webrtc/modules/audio_mixer/audio_mixer.h
diff --git a/webrtc/modules/audio_mixer/audio_mixer.h b/webrtc/modules/audio_mixer/audio_mixer.h
index 6f0329b658d7bbc781dd7e0f91c200c4fac461cf..f1595bd02600138b8569071f2440281980ecbf10 100644
--- a/webrtc/modules/audio_mixer/audio_mixer.h
+++ b/webrtc/modules/audio_mixer/audio_mixer.h
@@ -18,7 +18,6 @@
 #include "webrtc/modules/include/module_common_types.h"
 
 namespace webrtc {
-class MixerAudioSource;
 
 class AudioMixer {
  public:
@@ -53,7 +52,7 @@ class AudioMixer {
   // 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,
+                   int number_of_channels,
                    AudioFrame* audio_frame_for_mixing) = 0;
 
   // Returns true if the audio source is mixed anonymously.