Implement Turn/Turn first logic for connection selection.

webrtc/p2p/base/transport.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 129 matching lines @@
 // Information about ICE configuration.
 struct IceConfig {
   // The ICE connection receiving timeout value.
   // TODO(honghaiz): Remove suffix _ms to be consistent.
   int receiving_timeout_ms = -1;
   // Time interval in milliseconds to ping a backup connection when the ICE
   // channel is strongly connected.
   int backup_connection_ping_interval = -1;
   // If true, the most recent port allocator session will keep on running.
   bool gather_continually = false;
+  bool ping_most_likely_candidate_pair_first = false;

[pthatcher1, 2016/01/27 19:59:59]

And here, the name could be the same but without "ice" in it:
prioritize_most_likely_candidate_pairs

[guoweis_webrtc, 2016/02/29 18:03:01]

Done.

 };
 
 bool BadTransportDescription(const std::string& desc, std::string* err_desc);
 
 bool IceCredentialsChanged(const std::string& old_ufrag,
                            const std::string& old_pwd,
                            const std::string& new_ufrag,
                            const std::string& new_pwd);
 
 class Transport : public sigslot::has_slots<> {
@@ skipping 157 matching lines @@
 
   ChannelMap channels_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(Transport);
 };
 
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_TRANSPORT_H_