Add 'title' field to DownloadUIItem and thread through bridges to OfflinePageDownloadItem.

components/offline_pages/downloads/download_ui_item.h

 // Copyright 2016 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 COMPONENTS_OFFLINE_PAGES_DOWNLOADS_DOWNLOAD_UI_ITEM_H_
 #define COMPONENTS_OFFLINE_PAGES_DOWNLOADS_DOWNLOAD_UI_ITEM_H_
 
 #include <stdint.h>
 
 #include <string>
@@ skipping 10 matching lines @@
   DownloadUIItem();
   explicit DownloadUIItem(const OfflinePageItem& page);
   ~DownloadUIItem();
 
   // Unique id.
   std::string guid;
 
   // The URL of the captured page.
   GURL url;
 
+  // The Title of the captured page, if any. It can be empty string either
+  // because the page is not yet fully loaded, or because it doesn't have any.
+  base::string16 title;
+
   // The file path to the archive with a local copy of the page.
   base::FilePath target_path;
 
   // The time when the offline archive was created.
   base::Time start_time;
 
   // The size of the offline copy.
   int64_t total_bytes;
 };
 
 }  // namespace offline_pages
 
 #endif  // COMPONENTS_OFFLINE_PAGES_DOWNLOADS_DOWNLOAD_UI_ITEM_H_