remoting/host: Fix cpplint warning of header guards.

remoting/host/disconnect_window.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_DISCONNECT_WINDOW_H
-#define REMOTING_HOST_DISCONNECT_WINDOW_H
+#ifndef REMOTING_HOST_DISCONNECT_WINDOW_H_
+#define REMOTING_HOST_DISCONNECT_WINDOW_H_
+#pragma once
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/memory/scoped_ptr.h"
 
 namespace remoting {
 
 class ChromotingHost;
 
 class DisconnectWindow {
  public:
-
   enum {
     kMaximumConnectedNameWidthInPixels = 400
   };
 
   // DisconnectCallback is called when the user clicks on the Disconnect button
   // to disconnect the session. This callback is provided as a parameter to the
   // Show() method, and will be triggered on the UI thread.
   typedef base::Callback<void(void)> DisconnectCallback;
 
   virtual ~DisconnectWindow() {}
 
   // Show the disconnect window allowing the user to shut down |host|.
   virtual void Show(ChromotingHost* host,
                     const DisconnectCallback& disconnect_callback,
                     const std::string& username) = 0;
 
   // Hide the disconnect window.
   virtual void Hide() = 0;
 
   static scoped_ptr<DisconnectWindow> Create();
 };
 
-}
+}  // namespace remoting
 
-#endif  // REMOTING_HOST_DISCONNECT_WINDOW_H
+#endif  // REMOTING_HOST_DISCONNECT_WINDOW_H_