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

webrtc/p2p/base/port.h

 /*
  *  Copyright 2004 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 160 matching lines @@
   void set_component(int component) { component_ = component; }
 
   bool send_retransmit_count_attribute() const {
     return send_retransmit_count_attribute_;
   }
   void set_send_retransmit_count_attribute(bool enable) {
     send_retransmit_count_attribute_ = enable;
   }
 
   // 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;
   const std::string& password() const { return password_; }
 
   // May be called when this port was initially created by a pooled
   // PortAllocatorSession, and is now being assigned to an ICE transport.
   // Updates the information for candidates as well.
   void SetIceParameters(int component,
                         const std::string& username_fragment,
@@ skipping 486 matching lines @@
            const rtc::PacketOptions& options) override;
   int GetError() override { return error_; }
 
  private:
   int error_ = 0;
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_PORT_H_