[Downloads] Introduce GUIDs for downloads.

content/browser/download/download_item_factory.h

 // Copyright (c) 2012 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.
 //
 // The DownloadItemFactory is used to produce different DownloadItems.
 // It is separate from the DownloadManager to allow download manager
 // unit tests to control the items produced.
 
 #ifndef CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_FACTORY_H_
 #define CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_FACTORY_H_
@@ skipping 23 matching lines @@
 class DownloadItemImplDelegate;
 class DownloadRequestHandleInterface;
 struct DownloadCreateInfo;
 
 class DownloadItemFactory {
 public:
   virtual ~DownloadItemFactory() {}
 
   virtual DownloadItemImpl* CreatePersistedItem(
       DownloadItemImplDelegate* delegate,
+      const std::string& guid,
       uint32_t download_id,
       const base::FilePath& current_path,
       const base::FilePath& target_path,
       const std::vector<GURL>& url_chain,
       const GURL& referrer_url,
       const std::string& mime_type,
       const std::string& original_mime_type,
       const base::Time& start_time,
       const base::Time& end_time,
       const std::string& etag,
@@ skipping 18 matching lines @@
       const base::FilePath& path,
       const GURL& url,
       const std::string& mime_type,
       scoped_ptr<DownloadRequestHandleInterface> request_handle,
       const net::BoundNetLog& bound_net_log) = 0;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DOWNLOAD_DOWNLOAD_ITEM_FACTORY_H_