Virtual destructors should have virtual keyword.

chrome/browser/content_settings/host_content_settings_map.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.
 
 // Maps hostnames to custom content settings.  Written on the UI thread and read
 // on any thread.  One instance per profile.
 
 #ifndef CHROME_BROWSER_CONTENT_SETTINGS_HOST_CONTENT_SETTINGS_MAP_H_
 #define CHROME_BROWSER_CONTENT_SETTINGS_HOST_CONTENT_SETTINGS_MAP_H_
 #pragma once
@@ skipping 149 matching lines @@
 
   // NotificationObserver implementation.
   virtual void Observe(NotificationType type,
                        const NotificationSource& source,
                        const NotificationDetails& details);
 
  private:
   friend struct BrowserThread::DeleteOnThread<BrowserThread::UI>;
   friend class DeleteTask<HostContentSettingsMap>;
 
-  ~HostContentSettingsMap();
+  virtual ~HostContentSettingsMap();
 
   void UnregisterObservers();
 
   // Various migration methods (old cookie, popup and per-host data gets
   // migrated to the new format).
   void MigrateObsoleteCookiePref(PrefService* prefs);
 
   // The profile we're associated with.
   Profile* profile_;
 
@@ skipping 19 matching lines @@
   mutable base::Lock lock_;
 
   // Misc global settings.
   bool block_third_party_cookies_;
   bool is_block_third_party_cookies_managed_;
 
   DISALLOW_COPY_AND_ASSIGN(HostContentSettingsMap);
 };
 
 #endif  // CHROME_BROWSER_CONTENT_SETTINGS_HOST_CONTENT_SETTINGS_MAP_H_