Fix a bug where redirect chain gets lost on process swap.

chrome/browser/renderer_host/chrome_url_request_user_data.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_RENDERER_HOST_CHROME_URL_REQUEST_USER_DATA_H_
 #define CHROME_BROWSER_RENDERER_HOST_CHROME_URL_REQUEST_USER_DATA_H_
 #pragma once
 
 #include "net/url_request/url_request.h"
 
 class ChromeURLRequestUserData : public net::URLRequest::UserData {
  public:
   bool is_prerender() const { return is_prerender_; }
   void set_is_prerender(bool is_prerender) { is_prerender_ = is_prerender; }
 
   // Creates a new ChromeURLRequestUserData instance and attaches it
   // to |request|. |request| must not have an existing ChromeURLRequestUserData
   // instance attached to it, and must be non-NULL. The returned instance
   // is owned by |request|.
   static ChromeURLRequestUserData* Create(net::URLRequest* request);
 
+  // Delete the ChromeURLRequestUserData from a |request|. |request| must be
+  // non-NULL.
+  static void Delete(net::URLRequest* request);
+
   // Gets the ChromeURLRequestUserData instance attached to |request|, or
   // returns NULL if one is not attached. |request| must be non-NULL.
   static ChromeURLRequestUserData* Get(const net::URLRequest* request);
 
  private:
   ChromeURLRequestUserData();
 
   bool is_prerender_;
 
   DISALLOW_COPY_AND_ASSIGN(ChromeURLRequestUserData);
 };
 
 #endif  // CHROME_BROWSER_RENDERER_HOST_CHROME_URL_REQUEST_USER_DATA_H_