Issue 4795 - Use modern JavaScript syntax

qunit/common.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 25 matching lines @@
   ElemHide.clear();
 }
 
 function restoreFilterComponents()
 {
 }
 
 function preparePrefs()
 {
   this._pbackup = Object.create(null);
-  for (var pref in Prefs)
+  for (let pref in Prefs)
   {
-    var value = Prefs[pref];
+    let value = Prefs[pref];
     this._pbackup[pref] = value;
   }
   Prefs.enabled = true;
 }
 
 function restorePrefs()
 {
-  for (var pref in this._pbackup)
+  for (let pref in this._pbackup)
     Prefs[pref] = this._pbackup[pref];
 }
 
 function executeFirstRunActions()
 {
 }