Virtual destructors should have virtual keyword.

chrome/browser/extensions/extension_host.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_EXTENSIONS_EXTENSION_HOST_H_
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_HOST_H_
 #pragma once
 
 #include <string>
 #include <vector>
@@ skipping 33 matching lines @@
                       public NotificationObserver,
                       public JavaScriptAppModalDialogDelegate {
  public:
   class ProcessCreationQueue;
 
   // Enable DOM automation in created render view hosts.
   static void EnableDOMAutomation() { enable_dom_automation_ = true; }
 
   ExtensionHost(const Extension* extension, SiteInstance* site_instance,
                 const GURL& url, ViewType::Type host_type);
-  ~ExtensionHost();
+  virtual ~ExtensionHost();
 
 #if defined(TOOLKIT_VIEWS)
   void set_view(ExtensionView* view) { view_.reset(view); }
   const ExtensionView* view() const { return view_.get(); }
   ExtensionView* view() { return view_.get(); }
 #elif defined(OS_MACOSX)
   const ExtensionViewMac* view() const { return view_.get(); }
   ExtensionViewMac* view() { return view_.get(); }
 #elif defined(TOOLKIT_GTK)
   const ExtensionViewGtk* view() const { return view_.get(); }
@@ skipping 229 matching lines @@
   // The time that the last javascript message was dismissed.
   base::TimeTicks last_javascript_message_dismissal_;
 
   // Whether to suppress all javascript messages.
   bool suppress_javascript_messages_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionHost);
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_HOST_H_