Remove first_message argument from AuthenticatorFactory::Create().

remoting/protocol/jingle_session_manager.cc

Index: remoting/protocol/jingle_session_manager.cc
diff --git a/remoting/protocol/jingle_session_manager.cc b/remoting/protocol/jingle_session_manager.cc
index f3c53b983c53b2e3ec6e329c502e06f1a5d1cffc..f7872cf96f674022833582786ae993fc580125ab 100644
--- a/remoting/protocol/jingle_session_manager.cc
+++ b/remoting/protocol/jingle_session_manager.cc
@@ -82,8 +82,7 @@ bool JingleSessionManager::OnSignalStrategyIncomingStanza(
 
     scoped_ptr<Authenticator> authenticator =
         authenticator_factory_->CreateAuthenticator(
-            signal_strategy_->GetLocalJid(), message.from,
-            message.description->authenticator_message());
+            signal_strategy_->GetLocalJid(), message.from);
 
     JingleSession* session = new JingleSession(this);
     session->InitializeIncomingConnection(message, std::move(authenticator));