Virtual destructors should have virtual keyword.

chrome/browser/omnibox_search_hint.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_OMNIBOX_SEARCH_HINT_H_
 #define CHROME_BROWSER_OMNIBOX_SEARCH_HINT_H_
 #pragma once
 
 #include <map>
 #include <string>
 
 #include "content/common/notification_observer.h"
 #include "content/common/notification_registrar.h"
 
 class Profile;
 class TabContentsWrapper;
 
 // This class is responsible for showing an info-bar that tells the user she
 // can type her search query directly in the omnibox.
 // It is displayed when the user visits a known search engine URL and has not
 // searched from the omnibox before, or has not previously dismissed a similar
 // info-bar.
 class OmniboxSearchHint : public NotificationObserver {
  public:
   explicit OmniboxSearchHint(TabContentsWrapper* tab);
-  ~OmniboxSearchHint();
+  virtual ~OmniboxSearchHint();
 
   // NotificationObserver method:
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
   // Focus the location bar and displays a message instructing that search
   // queries can be typed directly in there.
   void ShowEnteringQuery();
 
@@ skipping 15 matching lines @@
   TabContentsWrapper* tab_;
 
   // A map containing the URLs of the search engine for which we want to
   // trigger the hint.
   std::map<std::string, int> search_engine_urls_;
 
   DISALLOW_COPY_AND_ASSIGN(OmniboxSearchHint);
 };
 
 #endif  // CHROME_BROWSER_OMNIBOX_SEARCH_HINT_H_