Add ufrag to the ICE candidate signaling.

webrtc/p2p/base/p2ptransportchannel.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 241 matching lines @@
   IceRole ice_role_;
   uint64_t tiebreaker_;
   uint32_t remote_candidate_generation_;
   IceGatheringState gathering_state_;
 
   int check_receiving_delay_;
   int receiving_timeout_;
   uint32_t last_ping_sent_ms_ = 0;
   bool gather_continually_ = false;
   int weak_ping_delay_ = WEAK_PING_DELAY;
+  // Keep a set of old remote ufrags so that we know whether a ufrag is new.
+  std::set<std::string> old_remote_ufrags_;

[pthatcher1, 2015/12/04 20:43:50]

I think a good name for this would be remote_generations_.  And then maybe store
a struct of IceGenerations like this:

struct IceGeneration {
  std::string ufrag;
}

Then later, we could possibly add other things, like pwd.

Additionally, I think we should put the current one in there and have
remote_ufrag() and remote_pwd() getters return remote_generations_[0]...

[honghaiz3, 2015/12/09 23:57:54]

Done. added the pwd there too.

 
   RTC_DISALLOW_COPY_AND_ASSIGN(P2PTransportChannel);
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_P2PTRANSPORTCHANNEL_H_