Virtual destructors should have virtual keyword.

chrome/browser/ui/webui/ntp/new_tab_ui.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_NEW_TAB_UI_H_
 #define CHROME_BROWSER_UI_WEBUI_NTP_NEW_TAB_UI_H_
 #pragma once
 
 #include <string>
 
 #include "base/gtest_prod_util.h"
 #include "base/timer.h"
 #include "chrome/browser/sessions/tab_restore_service.h"
 #include "chrome/browser/ui/webui/chrome_url_data_manager.h"
 #include "content/browser/webui/web_ui.h"
 #include "content/common/notification_observer.h"
 #include "content/common/notification_registrar.h"
 
 class GURL;
 class MessageLoop;
 class PrefService;
 class Profile;
 
 // The TabContents used for the New Tab page.
 class NewTabUI : public WebUI,
                  public NotificationObserver {
  public:
   explicit NewTabUI(TabContents* manager);
-  ~NewTabUI();
+  virtual ~NewTabUI();
 
   // Override WebUI methods so we can hook up the paint timer to the render
   // view host.
   virtual void RenderViewCreated(RenderViewHost* render_view_host);
   virtual void RenderViewReused(RenderViewHost* render_view_host);
 
   static void RegisterUserPrefs(PrefService* prefs);
   static void MigrateUserPrefs(PrefService* prefs, int old_pref_version,
                                int new_pref_version);
 
@@ skipping 71 matching lines @@
   base::TimeTicks last_paint_;
   // Scoping so we can be sure our timeouts don't outlive us.
   base::OneShotTimer<NewTabUI> timer_;
   // The preference version. This used for migrating prefs of the NTP.
   static const int current_pref_version_ = 3;
 
   DISALLOW_COPY_AND_ASSIGN(NewTabUI);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_NTP_NEW_TAB_UI_H_