[NOT FOR REVIEW] Convert channel counts to size_t.

webrtc/voice_engine/utility.h

Index: webrtc/voice_engine/utility.h
diff --git a/webrtc/voice_engine/utility.h b/webrtc/voice_engine/utility.h
index 87003c42581cd99337e3176fb3b1c2c772d438bc..5aa6a6adb4e3371c6d774126ae77ec5245e7509c 100644
--- a/webrtc/voice_engine/utility.h
+++ b/webrtc/voice_engine/utility.h
@@ -43,18 +43,18 @@ void RemixAndResample(const AudioFrame& src_frame,
 // it shouldn't be needed.
 void DownConvertToCodecFormat(const int16_t* src_data,
                               size_t samples_per_channel,
-                              int num_channels,
+                              size_t num_channels,
                               int sample_rate_hz,
-                              int codec_num_channels,
+                              size_t codec_num_channels,
                               int codec_rate_hz,
                               int16_t* mono_buffer,
                               PushResampler<int16_t>* resampler,
                               AudioFrame* dst_af);
 
 void MixWithSat(int16_t target[],
-                int target_channel,
+                size_t target_channel,
                 const int16_t source[],
-                int source_channel,
+                size_t source_channel,
                 size_t source_len);
 
 }  // namespace voe