Only set certificate on DTLS transport if fingerprint is found in SDP.

webrtc/p2p/base/jseptransport.cc

 /*
  *  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 311 matching lines @@
   desc << fp_tmp->ToString();
   desc << " Got: " << fingerprint->ToString();
   return BadTransportDescription(desc.str(), error_desc);
 }
 
 bool JsepTransport::ApplyLocalTransportDescription(
     DtlsTransportInternal* dtls_transport,
     std::string* error_desc) {
   dtls_transport->ice_transport()->SetIceParameters(
       local_description_->GetIceParameters());
-  return true;
+  bool ret = true;
+  if (certificate_) {
+    ret = dtls_transport->SetLocalCertificate(certificate_);
+    RTC_DCHECK(ret);
+  }
+  return ret;
 }
 
 bool JsepTransport::ApplyRemoteTransportDescription(
     DtlsTransportInternal* dtls_transport,
     std::string* error_desc) {
   // Currently, all ICE-related calls still go through this DTLS channel. But
   // that will change once we get rid of TransportChannelImpl, and the DTLS
   // channel interface no longer includes ICE-specific methods. Then this class
   // will need to call dtls->ice()->SetIceRole(), for example, assuming the Dtls
   // interface will expose its inner ICE channel.
@@ skipping 135 matching lines @@
     }
 
     // If local is passive, local will act as server.
   }
 
   *ssl_role = is_remote_server ? rtc::SSL_CLIENT : rtc::SSL_SERVER;
   return true;
 }
 
 }  // namespace cricket