Relanding: Allow the DTLS fingerprint verification to occur after the handshake.

webrtc/p2p/base/dtlstransportchannel.h

 /*
  *  Copyright 2011 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 175 matching lines @@
     channel_->RemoveRemoteCandidate(candidate);
   }
 
   void SetIceConfig(const IceConfig& config) override {
     channel_->SetIceConfig(config);
   }
 
   // Needed by DtlsTransport.
   TransportChannelImpl* channel() { return channel_; }
 
+  // For informational purposes. Tells if the DTLS handshake has finished.
+  // This may be true even if writable() is false, if the remote fingerprint
+  // has not yet been verified.
+  bool IsDtlsConnected();
+
  private:
-  void OnReadableState(TransportChannel* channel);
   void OnWritableState(TransportChannel* channel);
   void OnReadPacket(TransportChannel* channel, const char* data, size_t size,
                     const rtc::PacketTime& packet_time, int flags);
   void OnSentPacket(TransportChannel* channel,
                     const rtc::SentPacket& sent_packet);
   void OnReadyToSend(TransportChannel* channel);
   void OnReceivingState(TransportChannel* channel);
   void OnDtlsEvent(rtc::StreamInterface* stream_, int sig, int err);
   bool SetupDtls();
   void MaybeStartDtls();
@@ skipping 30 matching lines @@
   // transport channel became writable, or before a remote fingerprint was
   // received.
   rtc::Buffer cached_client_hello_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(DtlsTransportChannelWrapper);
 };
 
 }  // namespace cricket
 
 #endif  // WEBRTC_P2P_BASE_DTLSTRANSPORTCHANNEL_H_