[NOT FOR REVIEW] Convert channel counts to size_t.

webrtc/modules/rtp_rtcp/source/rtp_sender_audio.cc

 /*
  *  Copyright (c) 2012 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 53 matching lines @@
     CriticalSectionScoped cs(_sendAudioCritsect.get());
 
     _packetSizeSamples = packetSizeSamples;
     return 0;
 }
 
 int32_t RTPSenderAudio::RegisterAudioPayload(
     const char payloadName[RTP_PAYLOAD_NAME_SIZE],
     const int8_t payloadType,
     const uint32_t frequency,
-    const uint8_t channels,
+    const size_t channels,
     const uint32_t rate,
     RtpUtility::Payload*& payload) {
   if (RtpUtility::StringCompare(payloadName, "cn", 2)) {
     CriticalSectionScoped cs(_sendAudioCritsect.get());
     //  we can have multiple CNG payload types
     switch (frequency) {
       case 8000:
         _cngNBPayloadType = payloadType;
         break;
       case 16000:
@@ skipping 396 matching lines @@
         retVal = _rtpSender->SendToNetwork(dtmfbuffer, 4, 12, -1,
                                            kAllowRetransmission,
                                            PacedSender::kHighPriority);
         sendCount--;
 
     }while (sendCount > 0 && retVal == 0);
 
     return retVal;
 }
 }  // namespace webrtc