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

webrtc/p2p/base/port.h

Index: webrtc/p2p/base/port.h
diff --git a/webrtc/p2p/base/port.h b/webrtc/p2p/base/port.h
index 5d95b80a5be8cc0dd7cec3e7e9f02215ec5794ad..54f7acd7ac84089918889015866d0725bd69b07d 100644
--- a/webrtc/p2p/base/port.h
+++ b/webrtc/p2p/base/port.h
@@ -178,7 +178,7 @@ class Port : public PortInterface, public rtc::MessageHandler,
   }
 
   // Identifies the generation that this port was created in.
-  uint32_t generation() { return generation_; }
+  uint32_t generation() const { return generation_; }
   void set_generation(uint32_t generation) { generation_ = generation; }
 
   const std::string username_fragment() const;