Issue 1602 - Use ES6 generators instead of legacy generators

lib/synchronizer.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 70 matching lines @@
    * @param {Boolean} manual  true for a manually started download (should not trigger fallback requests)
    */
   execute: function(subscription, manual)
   {
     downloader.download(this._getDownloadable(subscription, manual));
   },
 
   /**
    * Yields Downloadable instances for all subscriptions that can be downloaded.
    */
-  _getDownloadables: function()
+  _getDownloadables: function*()
   {
     if (!Prefs.subscriptions_autoupdate)
       return;
 
     for (let subscription of FilterStorage.subscriptions)
     {
       if (subscription instanceof DownloadableSubscription)
         yield this._getDownloadable(subscription, false);
     }
   },
@@ skipping 209 matching lines @@
             let data = "[Adblock]\n" + subscription.filters.map((f) => f.text).join("\n");
             redirectCallback("data:text/plain," + encodeURIComponent(data));
           }
         }, false);
         request.send(null);
       }
     }
   },
 };
 Synchronizer.init();