Add checks to DEBUG mode that no instance of URLRequest or URLFetcher survive...

chrome/browser/net/url_fetcher.h

 // Copyright (c) 2009 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 file contains URLFetcher, a wrapper around URLRequest that handles
 // low-level details like thread safety, ref counting, and incremental buffer
 // reading.  This is useful for callers who simply want to get the data from a
 // URL and don't care about all the nitty-gritty details.
 
 #ifndef CHROME_BROWSER_URL_FETCHER_H_
 #define CHROME_BROWSER_URL_FETCHER_H_
 
+#include "base/leak_tracker.h"
 #include "base/message_loop.h"
 #include "base/ref_counted.h"
 #include "chrome/browser/net/url_fetcher_protect.h"
 
 class GURL;
 typedef std::vector<std::string> ResponseCookies;
 class URLFetcher;
 class URLRequestContext;
 class URLRequestStatus;
 
@@ skipping 133 matching lines @@
   // are used to ensure that all handling of URLRequests happens on the IO
   // thread (since that class is not currently threadsafe and relies on
   // underlying Microsoft APIs that we don't know to be threadsafe), while
   // keeping the delegate callback on the delegate's thread.
   class Core;
 
   scoped_refptr<Core> core_;
 
   static Factory* factory_;
 
+  base::LeakTracker<URLFetcher> leak_tracker_;
+
   DISALLOW_EVIL_CONSTRUCTORS(URLFetcher);
 };
 
 #endif  // CHROME_BROWSER_URL_FETCHER_H_