Virtual destructors should have virtual keyword.

chrome/browser/net/url_request_failed_dns_job.h

 // Copyright (c) 2010 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.
 // This class simulates what wininet does when a dns lookup fails.
 
 #ifndef CHROME_BROWSER_NET_URL_REQUEST_FAILED_DNS_JOB_H_
 #define CHROME_BROWSER_NET_URL_REQUEST_FAILED_DNS_JOB_H_
 #pragma once
 
 #include "base/task.h"
 #include "net/url_request/url_request_job.h"
 
 class URLRequestFailedDnsJob : public net::URLRequestJob {
  public:
   explicit URLRequestFailedDnsJob(net::URLRequest* request);
 
   virtual void Start();
 
   static net::URLRequestJob* Factory(net::URLRequest* request,
                                      const std::string& scheme);
 
   // A test URL that can be used in UI tests.
   static const char kTestUrl[];
 
   // Adds the testing URLs to the net::URLRequestFilter.
   static void AddUrlHandler();
 
  private:
-  ~URLRequestFailedDnsJob();
+  virtual ~URLRequestFailedDnsJob();
 
   // Simulate a DNS failure.
   void StartAsync();
 
   ScopedRunnableMethodFactory<URLRequestFailedDnsJob> method_factory_;
 };
 
 #endif  // CHROME_BROWSER_NET_URL_REQUEST_FAILED_DNS_JOB_H_