Issue 3868 - Use the new FilterNotifier API

lib/subscriptionInit.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2016 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 13 matching lines @@
 let {FilterStorage} = require("filterStorage");
 let {FilterNotifier} = require("filterNotifier");
 let {Prefs} = require("prefs");
 let {Synchronizer} = require("synchronizer");
 let {Utils} = require("utils");
 let {initNotifications} = require("notificationHelper");
 
 let firstRun;
 let subscriptionsCallback = null;
 
-let filtersLoaded = new Promise(resolve =>
-{
-  function onFilterAction(action)
-  {
-    if (action == "load")
-    {
-      FilterNotifier.removeListener(onFilterAction);
-      resolve();
-    }
-  }
-  FilterNotifier.addListener(onFilterAction);
-});
-
 /**
  * If there aren't any filters, the default subscriptions are added.
  * However, if patterns.ini already did exist and/or any preference
  * is set to a non-default value, this indicates that this isn't the
  * first run, but something went wrong.
  *
  * This function detects the first run, and makes sure that the user
  * gets notified (on the first run page) if the data appears incomplete
  * and therefore will be reinitialized.
  */
@@ skipping 108 matching lines @@
         !subscription.lastDownload)
       Synchronizer.execute(subscription);
   }
 
   if (firstRun && !Prefs.suppress_first_run_page)
     ext.pages.open(ext.getURL("firstRun.html"));
 
   initNotifications();
 }
 
-Promise.all([filtersLoaded, Prefs.untilLoaded]).then(detectFirstRun)
-                                            .then(getSubscriptions)
-                                            .then(finishInitialization);
+Promise.all([FilterNotifier.once("load"),
+             Prefs.untilLoaded]).then(detectFirstRun)
+                                .then(getSubscriptions)
+                                .then(finishInitialization);
 
 /**
  * Indicates whether the default filter subscriptions have been added
  * again because there weren't any subscriptions even though this wasn't
  * the first run.
  *
  * @type {boolean}
  */
 exports.reinitialized = false;
 
 /**
  * Sets a callback that is called with an array of subscriptions to be added
  * during initialization. The callback must return an array of subscriptions
  * that will effectively be added.
  *
  * @param {function}
  */
 exports.setSubscriptionsCallback = function(callback)
 {
   subscriptionsCallback = callback;
 };