Virtual destructors should have virtual keyword.

chrome/browser/extensions/extension_context_menu_api.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_CONTEXT_MENU_API_H__
 #define CHROME_BROWSER_EXTENSIONS_EXTENSION_CONTEXT_MENU_API_H__
 #pragma once
 
 #include "chrome/browser/extensions/extension_function.h"
 #include "chrome/browser/extensions/extension_menu_manager.h"
 #include "chrome/common/extensions/url_pattern_set.h"
 
 class DictionaryValue;
 class ExtensionMenuItem;
 
 class ExtensionContextMenuFunction : public SyncExtensionFunction {
  public:
-  ~ExtensionContextMenuFunction() {}
+  virtual ~ExtensionContextMenuFunction() {}
 
  protected:
   // Helper function to read and parse a list of menu item contexts.
   bool ParseContexts(const DictionaryValue& properties,
                      const char* key,
                      ExtensionMenuItem::ContextList* result);
 
   // Looks in properties for the "type" key, and reads the value in |result|. On
   // error, returns false and puts an error message into error_. If the key is
   // not present, |result| is set to |default_value| and the return value is
@@ skipping 24 matching lines @@
   // on error, with an explanation written into error_. Note that if the
   // parentId key is not in properties, this will return true and leave |result|
   // unset. Also, it is considered an error if the item found has a type other
   // than NORMAL.
   bool GetParent(const DictionaryValue& properties,
                  const ExtensionMenuManager& manager,
                  ExtensionMenuItem** result);
 };
 
 class CreateContextMenuFunction : public ExtensionContextMenuFunction {
-  ~CreateContextMenuFunction() {}
+  virtual ~CreateContextMenuFunction() {}
   virtual bool RunImpl();
   DECLARE_EXTENSION_FUNCTION_NAME("contextMenus.create")
 };
 
 class UpdateContextMenuFunction : public ExtensionContextMenuFunction {
-  ~UpdateContextMenuFunction() {}
+  virtual ~UpdateContextMenuFunction() {}
   virtual bool RunImpl();
   DECLARE_EXTENSION_FUNCTION_NAME("contextMenus.update")
 };
 
 class RemoveContextMenuFunction : public ExtensionContextMenuFunction {
-  ~RemoveContextMenuFunction() {}
+  virtual ~RemoveContextMenuFunction() {}
   virtual bool RunImpl();
   DECLARE_EXTENSION_FUNCTION_NAME("contextMenus.remove")
 };
 
 class RemoveAllContextMenusFunction : public ExtensionContextMenuFunction {
-  ~RemoveAllContextMenusFunction() {}
+  virtual ~RemoveAllContextMenusFunction() {}
   virtual bool RunImpl();
   DECLARE_EXTENSION_FUNCTION_NAME("contextMenus.removeAll")
 };
 
 #endif  // CHROME_BROWSER_EXTENSIONS_EXTENSION_CONTEXT_MENU_API_H__