Add UMA metrics for ICE regathering reasons.

webrtc/p2p/quic/quictransportchannel.h

 /*
  *  Copyright 2016 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 181 matching lines @@
   // QuicCryptoClientStream::ProofHandler overrides.
   // Called by client crypto handshake when cached proof is marked valid.
   void OnProofValid(
       const net::QuicCryptoClientConfig::CachedState& cached) override;
   // Called by the client crypto handshake when proof verification details
   // become available, either because proof verification is complete, or when
   // cached details are used.
   void OnProofVerifyDetailsAvailable(
       const net::ProofVerifyDetails& verify_details) override;
 
+  void SetMetricsObserver(webrtc::MetricsObserverInterface* observer) override {
+    channel_->SetMetricsObserver(observer);
+  }
+
   // Returns true if |quic_| has queued data which wasn't written due
   // to |channel_| being write blocked.
   bool HasDataToWrite() const;
   // Writes queued data for |quic_| when |channel_| is no longer write blocked.
   void OnCanWrite();
   // Connectivity state of QuicTransportChannel.
   QuicTransportState quic_state() const { return quic_state_; }
   // Creates a new QUIC stream that can send data.
   ReliableQuicStream* CreateQuicStream();
 
@@ skipping 83 matching lines @@
   rtc::scoped_refptr<rtc::RTCCertificate> local_certificate_;
   // Fingerprint of the remote peer. This must be set before we start QUIC.
   rtc::Optional<RemoteFingerprint> remote_fingerprint_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(QuicTransportChannel);
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_QUIC_QUICTRANSPORTCHANNEL_H_