Convert channel counts to size_t.

talk/media/base/fakemediaengine.h

 /*
  * libjingle
  * Copyright 2004 Google Inc.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *  1. Redistributions of source code must retain the above copyright notice,
  *     this list of conditions and the following disclaimer.
  *  2. Redistributions in binary form must reproduce the above copyright notice,
@@ skipping 350 matching lines @@
       renderer_->SetSink(this);
     }
     virtual ~VoiceChannelAudioSink() {
       if (renderer_) {
         renderer_->SetSink(NULL);
       }
     }
     void OnData(const void* audio_data,
                 int bits_per_sample,
                 int sample_rate,
-                int number_of_channels,
+                size_t number_of_channels,
                 size_t number_of_frames) override {}
     void OnClose() override { renderer_ = NULL; }
     AudioRenderer* renderer() const { return renderer_; }
 
    private:
     AudioRenderer* renderer_;
   };
 
   bool SetRecvCodecs(const std::vector<AudioCodec>& codecs) {
     if (fail_set_recv_codecs()) {
@@ skipping 557 matching lines @@
 
  private:
   std::vector<FakeDataMediaChannel*> channels_;
   std::vector<DataCodec> data_codecs_;
   DataChannelType last_channel_type_;
 };
 
 }  // namespace cricket
 
 #endif  // TALK_MEDIA_BASE_FAKEMEDIAENGINE_H_