Remove first_message argument from AuthenticatorFactory::Create().

remoting/protocol/me2me_host_authenticator_factory.h

Index: remoting/protocol/me2me_host_authenticator_factory.h
diff --git a/remoting/protocol/me2me_host_authenticator_factory.h b/remoting/protocol/me2me_host_authenticator_factory.h
index 18ad8d37b4ad0c3605fc7bc91484f02f64a5b551..0f1cc7d580b448e92ce1829cd151ebb8b8dd72b8 100644
--- a/remoting/protocol/me2me_host_authenticator_factory.h
+++ b/remoting/protocol/me2me_host_authenticator_factory.h
@@ -51,8 +51,7 @@ class Me2MeHostAuthenticatorFactory : public AuthenticatorFactory {
   // AuthenticatorFactory interface.
   scoped_ptr<Authenticator> CreateAuthenticator(
       const std::string& local_jid,
-      const std::string& remote_jid,
-      const buzz::XmlElement* first_message) override;
+      const std::string& remote_jid) override;
 
  private:
   // Used for all host authenticators.