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

webrtc/media/base/rtpdataengine_unittest.cc

Index: webrtc/media/base/rtpdataengine_unittest.cc
diff --git a/webrtc/media/base/rtpdataengine_unittest.cc b/webrtc/media/base/rtpdataengine_unittest.cc
index 35daee5aeb7110acbe6dc155aa50164214d40028..9d1e4859162fcca522f2fc4e6fc6c18bc5f44ab7 100644
--- a/webrtc/media/base/rtpdataengine_unittest.cc
+++ b/webrtc/media/base/rtpdataengine_unittest.cc
@@ -70,9 +70,10 @@ class RtpDataMediaChannelTest : public testing::Test {
   }
 
   cricket::RtpDataMediaChannel* CreateChannel(cricket::RtpDataEngine* dme) {
+    cricket::MediaConfig config;
     cricket::RtpDataMediaChannel* channel =
-        static_cast<cricket::RtpDataMediaChannel*>(dme->CreateChannel(
-            cricket::DCT_RTP));
+        static_cast<cricket::RtpDataMediaChannel*>(
+            dme->CreateChannel(cricket::DCT_RTP, config));
     channel->SetInterface(iface_.get());
     channel->SignalDataReceived.connect(
         receiver_.get(), &FakeDataReceiver::OnDataReceived);