[NOT FOR REVIEW] Convert channel counts to size_t.

webrtc/modules/audio_coding/codecs/ilbc/audio_encoder_ilbc.cc

 /*
  *  Copyright (c) 2014 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 36 matching lines @@
 }
 
 AudioEncoderIlbc::~AudioEncoderIlbc() {
   CHECK_EQ(0, WebRtcIlbcfix_EncoderFree(encoder_));
 }
 
 int AudioEncoderIlbc::SampleRateHz() const {
   return kSampleRateHz;
 }
 
-int AudioEncoderIlbc::NumChannels() const {
+size_t AudioEncoderIlbc::NumChannels() const {
   return 1;
 }
 
 size_t AudioEncoderIlbc::MaxEncodedBytes() const {
   return RequiredOutputSizeBytes();
 }
 
 size_t AudioEncoderIlbc::Num10MsFramesInNextPacket() const {
   return num_10ms_frames_per_packet_;
 }
@@ skipping 71 matching lines @@
   config.payload_type = codec_inst.pltype;
   return config;
 }
 }  // namespace
 
 AudioEncoderMutableIlbc::AudioEncoderMutableIlbc(const CodecInst& codec_inst)
     : AudioEncoderMutableImpl<AudioEncoderIlbc>(CreateConfig(codec_inst)) {
 }
 
 }  // namespace webrtc