Virtual destructors should have virtual keyword.

chrome/browser/ui/webui/shared_resources_data_source.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_UI_WEBUI_SHARED_RESOURCES_DATA_SOURCE_H_
 #define CHROME_BROWSER_UI_WEBUI_SHARED_RESOURCES_DATA_SOURCE_H_
 #pragma once
 
 #include "chrome/browser/ui/webui/chrome_url_data_manager.h"
 
 namespace net {
 class URLRequest;
 class URLRequestJob;
 }  // namespace net
 
 class GURL;
 
 // A DataSource for chrome://resources/ URLs.
 class SharedResourcesDataSource : public ChromeURLDataManager::DataSource {
  public:
   SharedResourcesDataSource();
 
   // Overridden from ChromeURLDataManager::DataSource:
   virtual void StartDataRequest(const std::string& path,
                                 bool is_incognito,
                                 int request_id);
   virtual std::string GetMimeType(const std::string&) const;
 
  private:
-  ~SharedResourcesDataSource();
+  virtual ~SharedResourcesDataSource();
 
   DISALLOW_COPY_AND_ASSIGN(SharedResourcesDataSource);
 };
 
 #endif  // CHROME_BROWSER_UI_WEBUI_SHARED_RESOURCES_DATA_SOURCE_H_