Set the preferred DSCP value for Rtp data channel to be DSCP_AF41.

webrtc/media/base/hybriddataengine.h

 /*
  *  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 17 matching lines @@
                    DataEngineInterface* second)
       : first_(first),
         second_(second) {
     codecs_ = first_->data_codecs();
     codecs_.insert(
         codecs_.end(),
         second_->data_codecs().begin(),
         second_->data_codecs().end());
   }
 
-  virtual DataMediaChannel* CreateChannel(DataChannelType data_channel_type) {
+  virtual DataMediaChannel* CreateChannel(DataChannelType data_channel_type,
+                                          const MediaConfig& config) {
     DataMediaChannel* channel = NULL;
     if (first_) {
-      channel = first_->CreateChannel(data_channel_type);
+      channel = first_->CreateChannel(data_channel_type, config);
     }
     if (!channel && second_) {
-      channel = second_->CreateChannel(data_channel_type);
+      channel = second_->CreateChannel(data_channel_type, config);
     }
     return channel;
   }
 
   virtual const std::vector<DataCodec>& data_codecs() { return codecs_; }
 
  private:
   std::unique_ptr<DataEngineInterface> first_;
   std::unique_ptr<DataEngineInterface> second_;
   std::vector<DataCodec> codecs_;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_BASE_HYBRIDDATAENGINE_H_