Log how often DTLS negotiation failed because of incompatible ciphersuites.

webrtc/api/webrtcsession.h

 /*
  *  Copyright 2012 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 425 matching lines @@
   // Reports stats for all transports in use.
   void ReportTransportStats();
 
   // Gather the usage of IPv4/IPv6 as best connection.
   void ReportBestConnectionState(const cricket::TransportStats& stats);
 
   void ReportNegotiatedCiphers(const cricket::TransportStats& stats);
 
   void OnSentPacket_w(const rtc::SentPacket& sent_packet);
 
+  void OnDtlsHandshakeError(int error);
+
   rtc::Thread* const worker_thread_;
   rtc::Thread* const signaling_thread_;
 
   State state_ = STATE_INIT;
   Error error_ = ERROR_NONE;
   std::string error_desc_;
 
   const std::string sid_;
   bool initial_offerer_ = false;
 
@@ skipping 36 matching lines @@
   PeerConnectionInterface::RtcpMuxPolicy rtcp_mux_policy_;
 
   bool received_first_video_packet_ = false;
   bool received_first_audio_packet_ = false;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(WebRtcSession);
 };
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_WEBRTCSESSION_H_