Added support for multiple urls in the component updater.

chrome/browser/component_updater/crx_update_item.h

 // Copyright 2013 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_COMPONENT_UPDATER_CRX_UPDATE_ITEM_H_
 #define CHROME_BROWSER_COMPONENT_UPDATER_CRX_UPDATE_ITEM_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 61 matching lines @@
 
   // Call CrxUpdateService::ChangeItemState to change |status|. The function may
   // enforce conditions or notify observers of the change.
   Status status;
 
   std::string id;
   CrxComponent component;
 
   base::Time last_check;
 
-  // The url the full and differential update CRXs are downloaded from.
-  GURL crx_url;
-  GURL diff_crx_url;
+  // A component can be made available for download from several urls.
+  std::vector<GURL> crx_urls;
+  std::vector<GURL> crx_diffurls;
 
   // The from/to version and fingerprint values.
   Version previous_version;
   Version next_version;
   std::string previous_fp;
   std::string next_fp;
 
   // True if the current update check cycle is on-demand.
   bool on_demand;
 
@@ skipping 29 matching lines @@
       return (item->id == id_);
     }
    private:
     const std::string& id_;
   };
 };
 
 }  // namespace component_updater
 
 #endif  // CHROME_BROWSER_COMPONENT_UPDATER_CRX_UPDATE_ITEM_H_