Add the URL attribute to cricket::Candiate.

webrtc/p2p/base/stunport.cc

Index: webrtc/p2p/base/stunport.cc
diff --git a/webrtc/p2p/base/stunport.cc b/webrtc/p2p/base/stunport.cc
index be844d54dc4bd8d0f72759471da831e4737206ef..43e8d9fb5c798c8d05ca7b89a99d1d1a2403998b 100644
--- a/webrtc/p2p/base/stunport.cc
+++ b/webrtc/p2p/base/stunport.cc
@@ -315,7 +315,7 @@ void UDPPort::OnLocalAddressReady(rtc::AsyncPacketSocket* socket,
   MaybeSetDefaultLocalAddress(&addr);
 
   AddAddress(addr, addr, rtc::SocketAddress(), UDP_PROTOCOL_NAME, "", "",
-             LOCAL_PORT_TYPE, ICE_TYPE_PREFERENCE_HOST, 0, false);
+             LOCAL_PORT_TYPE, ICE_TYPE_PREFERENCE_HOST, 0, "", false);
   MaybePrepareStunCandidate();
 }
 
@@ -453,9 +453,12 @@ void UDPPort::OnStunBindingRequestSucceeded(
           related_address.family());
     }
 
+    std::ostringstream url;
+    url << "stun:" << stun_server_addr.ipaddr().ToString() << ":"
+        << stun_server_addr.port();
     AddAddress(stun_reflected_addr, socket_->GetLocalAddress(), related_address,
                UDP_PROTOCOL_NAME, "", "", STUN_PORT_TYPE,
-               ICE_TYPE_PREFERENCE_SRFLX, 0, false);
+               ICE_TYPE_PREFERENCE_SRFLX, 0, url.str(), false);
   }
   MaybeSetPortCompleteOrError();
 }