remoting/host: Fix cpplint warning of header guards.

remoting/host/signaling_connector.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef REMOTING_HOST_SIGNALING_CONNECTOR_H
-#define REMOTING_HOST_SIGNALING_CONNECTOR_H
+#ifndef REMOTING_HOST_SIGNALING_CONNECTOR_H_
+#define REMOTING_HOST_SIGNALING_CONNECTOR_H_
+#pragma once
 
 #include "base/basictypes.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/non_thread_safe.h"
 #include "base/timer.h"
 #include "net/base/network_change_notifier.h"
 #include "remoting/host/gaia_oauth_client.h"
 #include "remoting/jingle_glue/xmpp_signal_strategy.h"
 
 namespace net {
@@ skipping 80 matching lines @@
   bool refreshing_oauth_token_;
   base::Time auth_token_expiry_time_;
 
   base::OneShotTimer<SignalingConnector> timer_;
 
   DISALLOW_COPY_AND_ASSIGN(SignalingConnector);
 };
 
 }  // namespace remoting
 
-#endif  // REMOTING_HOST_SIGNALING_CONNECTOR_H
+#endif  // REMOTING_HOST_SIGNALING_CONNECTOR_H_