Use scoped_ptr<> to pass ownership in more places.

remoting/host/disconnect_window.h

 // Copyright (c) 2011 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
 
 #include <string>
 
+#include "base/memory/scoped_ptr.h"
+
 namespace remoting {
 
 class ChromotingHost;
 
 class DisconnectWindow {
  public:
 
   enum {
     kMaximumConnectedNameWidthInPixels = 400
   };
 
   virtual ~DisconnectWindow() {}
 
   // Show the disconnect window allowing the user to shut down |host|.
   virtual void Show(ChromotingHost* host, const std::string& username) = 0;
 
   // Hide the disconnect window.
   virtual void Hide() = 0;
 
-  static DisconnectWindow* Create();
+  static scoped_ptr<DisconnectWindow> Create();
 };
 
 }
 
 #endif  // REMOTING_HOST_DISCONNECT_WINDOW_H