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

webrtc/p2p/base/tcpport.h

Index: webrtc/p2p/base/tcpport.h
diff --git a/webrtc/p2p/base/tcpport.h b/webrtc/p2p/base/tcpport.h
index 77bbd09eab0e2da449e72c6df467eb609e0044c8..2cb03246dcd2fcd3a65dc3daaed74f0612c65418 100644
--- a/webrtc/p2p/base/tcpport.h
+++ b/webrtc/p2p/base/tcpport.h
@@ -50,7 +50,8 @@ class TCPPort : public Port {
   ~TCPPort() override;
 
   Connection* CreateConnection(const Candidate& address,
-                               CandidateOrigin origin) override;
+                               CandidateOrigin origin,
+                               const IceConfig& config) override;
 
   void PrepareAddress() override;
 
@@ -120,7 +121,9 @@ class TCPPort : public Port {
 class TCPConnection : public Connection {
  public:
   // Connection is outgoing unless socket is specified
-  TCPConnection(TCPPort* port, const Candidate& candidate,
+  TCPConnection(TCPPort* port,
+                const Candidate& candidate,
+                const IceConfig& config,
                 rtc::AsyncPacketSocket* socket = 0);
   ~TCPConnection() override;