Remove first_message argument from AuthenticatorFactory::Create().

remoting/host/remoting_me2me_host.cc

Index: remoting/host/remoting_me2me_host.cc
diff --git a/remoting/host/remoting_me2me_host.cc b/remoting/host/remoting_me2me_host.cc
index 11fefc5099571264be9489e947f1974c9a549c2c..5018c13457f85831475d0898379e5f936e67b8fc 100644
--- a/remoting/host/remoting_me2me_host.cc
+++ b/remoting/host/remoting_me2me_host.cc
@@ -232,8 +232,7 @@ class NoopAuthenticatorFactory : public protocol::AuthenticatorFactory {
 
   scoped_ptr<protocol::Authenticator> CreateAuthenticator(
       const std::string& local_jid,
-      const std::string& remote_jid,
-      const buzz::XmlElement* first_message) override {
+      const std::string& remote_jid) override {
     return make_scoped_ptr(new NoopAuthenticator());
   }
 };