Virtual destructors should have virtual keyword.

chrome/browser/spellcheck_message_filter.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_SPELLCHECK_MESSAGE_FILTER_H_
 #define CHROME_BROWSER_SPELLCHECK_MESSAGE_FILTER_H_
 
 #include "content/browser/browser_message_filter.h"
 
 // A message filter implementation that receives
 // the platform spell checker requests from SpellCheckProvider.
 class SpellCheckMessageFilter : public BrowserMessageFilter {
  public:
   explicit SpellCheckMessageFilter(int render_process_id);
-  ~SpellCheckMessageFilter();
+  virtual ~SpellCheckMessageFilter();
 
   // BrowserMessageFilter implementation.
   virtual void OverrideThreadForMessage(const IPC::Message& message,
                                         BrowserThread::ID* thread);
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  bool* message_was_ok);
 
  private:
   void OnPlatformCheckSpelling(const string16& word, int tag, bool* correct);
   void OnPlatformFillSuggestionList(const string16& word,
                                     std::vector<string16>* suggestions);
   void OnGetDocumentTag(int* tag);
   void OnDocumentWithTagClosed(int tag);
   void OnShowSpellingPanel(bool show);
   void OnUpdateSpellingPanelWithMisspelledWord(const string16& word);
   void OnPlatformRequestTextCheck(int route_id,
                                   int identifier,
                                   int document_tag,
                                   const string16& text);
   void OnSpellCheckerRequestDictionary();
   void OnNotifyChecked(bool misspelled);
 
   int render_process_id_;
 };
 
 #endif  // CHROME_BROWSER_SPELLCHECK_MESSAGE_FILTER_H_