Virtual destructors should have virtual keyword.

chrome/browser/ui/webui/ntp/ntp_login_handler.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 CHROME_BROWSER_UI_WEBUI_NTP_NTP_LOGIN_HANDLER_H_
 #define CHROME_BROWSER_UI_WEBUI_NTP_NTP_LOGIN_HANDLER_H_
 #pragma once
 
 #include "chrome/browser/prefs/pref_member.h"
 #include "content/browser/webui/web_ui.h"
 #include "content/common/notification_observer.h"
 
 // The NTP login handler currently simply displays the current logged in
 // username at the top of the NTP (and update itself when that changes).
 // In the future it may expand to allow users to login from the NTP.
 class NTPLoginHandler : public WebUIMessageHandler,
                         public NotificationObserver {
  public:
   NTPLoginHandler();
-  ~NTPLoginHandler();
+  virtual ~NTPLoginHandler();
 
   virtual WebUIMessageHandler* Attach(WebUI* web_ui);
 
   // WebUIMessageHandler interface
   virtual void RegisterMessages();
 
   // NotificationObserver interface
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
  private:
   // Called from JS when the NTP is loaded.
   void HandleInitializeLogin(const ListValue* args);
 
   // Internal helper method
   void UpdateLogin();
 
   StringPrefMember username_pref_;
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_NTP_NTP_LOGIN_HANDLER_H_