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

webrtc/media/sctp/sctpdataengine.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 70 matching lines @@
 //  12. SctpDataMediaChannel::OnInboundPacketFromSctpToChannel(inboundpacket)
 //  13. SctpDataMediaChannel::OnDataFromSctpToChannel(data)
 //  14. SctpDataMediaChannel::SignalDataReceived(data)
 // [from the same thread, methods registered/connected to
 //  SctpDataMediaChannel are called with the recieved data]
 class SctpDataEngine : public DataEngineInterface, public sigslot::has_slots<> {
  public:
   SctpDataEngine();
   ~SctpDataEngine() override;
 
-  DataMediaChannel* CreateChannel(DataChannelType data_channel_type) override;
+  DataMediaChannel* CreateChannel(DataChannelType data_channel_type,
+                                  const MediaConfig& config) override;
   const std::vector<DataCodec>& data_codecs() override { return codecs_; }
 
  private:
   const std::vector<DataCodec> codecs_;
 };
 
 // TODO(ldixon): Make into a special type of TypedMessageData.
 // Holds data to be passed on to a channel.
 struct SctpInboundPacket;
 
@@ skipping 16 matching lines @@
     PPID_BINARY_PARTIAL = 52,
     PPID_BINARY_LAST = 53,
     PPID_TEXT_PARTIAL = 54,
     PPID_TEXT_LAST = 51
   };
 
   typedef std::set<uint32_t> StreamSet;
 
   // Given a thread which will be used to post messages (received data) to this
   // SctpDataMediaChannel instance.
-  explicit SctpDataMediaChannel(rtc::Thread* thread);
+  explicit SctpDataMediaChannel(rtc::Thread* thread, const MediaConfig& config);
   virtual ~SctpDataMediaChannel();
 
   // When SetSend is set to true, connects. When set to false, disconnects.
   // Calling: "SetSend(true); SetSend(false); SetSend(true);" will connect,
   // disconnect, and reconnect.
   virtual bool SetSend(bool send);
   // Unless SetReceive(true) is called, received packets will be discarded.
   virtual bool SetReceive(bool receive);
 
   virtual bool SetSendParameters(const DataSendParameters& params);
@@ skipping 101 matching lines @@
   StreamSet queued_reset_streams_;
   StreamSet sent_reset_streams_;
 
   // A static human-readable name for debugging messages.
   const char* debug_name_;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_MEDIA_SCTP_SCTPDATAENGINE_H_