Issue 2260 - Replaced some more for..in loops with for..of fixing the UI

lib/ui.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 391 matching lines @@
     // The icon might be added already, make sure its state is correct
     this.updateState();
 
     // Listen for pref and filters changes
     Prefs.addListener(function(name)
     {
       if (name == "enabled" || name == "defaulttoolbaraction" || name == "defaultstatusbaraction")
         this.updateState();
       else if (name == "showinstatusbar")
       {
-        for (let window in this.applicationWindows)
+        for (let window of this.applicationWindows)
           this.updateStatusbarIcon(window);
       }
     }.bind(this));
     FilterNotifier.addListener(function(action)
     {
       if (/^(filter|subscription)\.(added|removed|disabled|updated)$/.test(action) || action == "load")
         this.updateState();
     }.bind(this));
 
     notificationTimer = Cc["@mozilla.org/timer;1"].createInstance(Ci.nsITimer);
@@ skipping 655 matching lines @@
       let {defaultToolbarPosition} = require("appSupport");
       CustomizableUI.addWidgetToArea("abp-toolbarbutton", defaultToolbarPosition.parent);
     }
   },
 
   /**
    * Updates Adblock Plus icon state for all windows.
    */
   updateState: function()
   {
-    for (let window in this.applicationWindows)
+    for (let window of this.applicationWindows)
     {
       this.updateIconState(window, window.document.getElementById("abp-status"));
       this.updateIconState(window, window.document.getElementById("abp-toolbarbutton"));
     }
   },
 
   /**
    * Updates Adblock Plus icon state for a single application window.
    */
   updateIconState: function(/**Window*/ window, /**Element*/ icon)
@@ skipping 860 matching lines @@
   ["abp-command-togglesync", "command", UI.toggleSync.bind(UI)],
   ["abp-command-toggleshowintoolbar", "command", UI.toggleToolbarIcon.bind(UI)],
   ["abp-command-toggleshowinstatusbar", "command", UI.togglePref.bind(UI, "showinstatusbar")],
   ["abp-command-enable", "command", UI.togglePref.bind(UI, "enabled")],
   ["abp-command-contribute", "command", UI.openContributePage.bind(UI)],
   ["abp-command-contribute-hide", "command", UI.hideContributeButton.bind(UI)]
 ];
 
 onShutdown.add(function()
 {
-  for (let window in UI.applicationWindows)
+  for (let window of UI.applicationWindows)
     if (UI.isBottombarOpen(window))
       UI.toggleBottombar(window);
 });