Adding IceConfig option to assume TURN/TURN candidate pairs will work.

webrtc/p2p/base/portinterface.h

Index: webrtc/p2p/base/portinterface.h
diff --git a/webrtc/p2p/base/portinterface.h b/webrtc/p2p/base/portinterface.h
index e73861965e538e0ab8e09907d56b63241547c4b7..32b039a23f42f81f218902eb2d5ef364f21c92ca 100644
--- a/webrtc/p2p/base/portinterface.h
+++ b/webrtc/p2p/base/portinterface.h
@@ -66,10 +66,11 @@ class PortInterface {
   virtual Connection* GetConnection(
       const rtc::SocketAddress& remote_addr) = 0;
 
-  // Creates a new connection to the given address.
+  // Creates a new connection to the given address with the given ICE config.
   enum CandidateOrigin { ORIGIN_THIS_PORT, ORIGIN_OTHER_PORT, ORIGIN_MESSAGE };
-  virtual Connection* CreateConnection(
-      const Candidate& remote_candidate, CandidateOrigin origin) = 0;
+  virtual Connection* CreateConnection(const Candidate& remote_candidate,
+                                       CandidateOrigin origin,
+                                       const IceConfig& config) = 0;
 
   // Functions on the underlying socket(s).
   virtual int SetOption(rtc::Socket::Option opt, int value) = 0;