[NOT FOR REVIEW] Convert channel counts to size_t.

webrtc/modules/audio_coding/codecs/opus/opus_interface.c

Index: webrtc/modules/audio_coding/codecs/opus/opus_interface.c
diff --git a/webrtc/modules/audio_coding/codecs/opus/opus_interface.c b/webrtc/modules/audio_coding/codecs/opus/opus_interface.c
index e2a8383c4b665da3982843be94a360946d4f8d49..4ac29e9ab8114cd0f70eacc6f66571d92cdae58c 100644
--- a/webrtc/modules/audio_coding/codecs/opus/opus_interface.c
+++ b/webrtc/modules/audio_coding/codecs/opus/opus_interface.c
@@ -32,7 +32,7 @@ enum {
 };
 
 int16_t WebRtcOpus_EncoderCreate(OpusEncInst** inst,
-                                 int32_t channels,
+                                 size_t channels,
                                  int32_t application) {
   OpusEncInst* state;
   if (inst != NULL) {
@@ -55,7 +55,7 @@ int16_t WebRtcOpus_EncoderCreate(OpusEncInst** inst,
       }
 
       int error;
-      state->encoder = opus_encoder_create(48000, channels, opus_app,
+      state->encoder = opus_encoder_create(48000, (int)channels, opus_app,
                                            &error);
       state->in_dtx_mode = 0;
       if (error == OPUS_OK && state->encoder != NULL) {