Issue 5183 - Provide async interface for FileSystem

lib/init.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2017 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
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 let {Prefs} = require("prefs");
 let {FilterNotifier} = require("filterNotifier");
 
-let prefsInitDone = false;
 let filtersInitDone = false;
 
 function checkInitialized()
 {
-  if (prefsInitDone && filtersInitDone)
+  if (Prefs.initialized && filtersInitDone)
   {
     checkInitialized = function() {};
     _triggerEvent("_init", require("filterStorage").FilterStorage.firstRun);
   }
 }
 
 Prefs._initListener = function()
 {
-  prefsInitDone = true;
   checkInitialized();
 };
 
+if (Prefs.initialized)

[sergei, 2017/06/16 15:05:54]

Could you please move all these changes in JS files (init.js + prefs.js) into a
separate commit? I see the point we have to have such changes now, but they seem
to be valid, pretty useful and self contained.

[hub, 2017/06/16 21:52:54]

Done.

https://codereview.adblockplus.org/29467599

+  checkInitialized();
+
 FilterNotifier.addListener(function(action)
 {
   if (action === "load")
   {
     let {FilterStorage} = require("filterStorage");
     if (FilterStorage.firstRun)
     {
       // No data, must be a new user or someone with corrupted data - initialize
       // with default settings
 
@@ skipping 22 matching lines @@
         FilterStorage.addSubscription(aaSubscription);
         if (aaSubscription instanceof DownloadableSubscription && !aaSubscription.lastDownload)
           Synchronizer.execute(aaSubscription);
       }
     }
 
     filtersInitDone = true;
     checkInitialized();
   }
 });