Revert of Separating SCTP code from BaseChannel/MediaChannel.

webrtc/media/base/rtpdataengine.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 22 matching lines @@
 // buffer for it, otherwise SRTP will fail later.  If SRTP ever uses
 // more than this, we need to increase this number.
 static const size_t kMaxSrtpHmacOverhead = 16;
 
 RtpDataEngine::RtpDataEngine() {
   data_codecs_.push_back(
       DataCodec(kGoogleRtpDataCodecPlType, kGoogleRtpDataCodecName));
 }
 
 DataMediaChannel* RtpDataEngine::CreateChannel(
+    DataChannelType data_channel_type,
     const MediaConfig& config) {
+  if (data_channel_type != DCT_RTP) {
+    return NULL;
+  }
   return new RtpDataMediaChannel(config);
 }
 
 static const DataCodec* FindCodecByName(const std::vector<DataCodec>& codecs,
                                         const std::string& name) {
   for (const DataCodec& codec : codecs) {
     if (_stricmp(name.c_str(), codec.name.c_str()) == 0)
       return &codec;
   }
   return nullptr;
@@ skipping 283 matching lines @@
     *result = SDR_SUCCESS;
   }
   return true;
 }
 
 rtc::DiffServCodePoint RtpDataMediaChannel::PreferredDscp() const {
   return rtc::DSCP_AF41;
 }
 
 }  // namespace cricket