Log how often DTLS negotiation failed because of incompatible ciphersuites.

webrtc/api/umametrics.h

 /*
  *  Copyright 2014 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 14 matching lines @@
   // to the TURN server in the case of TURN candidates.
   kEnumCounterIceCandidatePairTypeUdp,
   kEnumCounterIceCandidatePairTypeTcp,
 
   kEnumCounterAudioSrtpCipher,
   kEnumCounterAudioSslCipher,
   kEnumCounterVideoSrtpCipher,
   kEnumCounterVideoSslCipher,
   kEnumCounterDataSrtpCipher,
   kEnumCounterDataSslCipher,
+  kEnumCounterDtlsHandshakeError,
   kPeerConnectionEnumCounterMax
 };
 
 // Currently this contains information related to WebRTC network/transport
 // information.
 
 // The difference between PeerConnectionEnumCounter and
 // PeerConnectionMetricsName is that the "EnumCounter" is only counting the
 // occurrences of events, while "Name" has a value associated with it which is
 // used to form a histogram.
@@ skipping 57 matching lines @@
   kIceCandidatePairHostPrivateHostPrivate,
   kIceCandidatePairHostPrivateHostPublic,
   kIceCandidatePairHostPublicHostPrivate,
   kIceCandidatePairHostPublicHostPublic,
   kIceCandidatePairMax
 };
 
 }  // namespace webrtc
 
 #endif  // WEBRTC_API_UMAMETRICS_H_