Issue 4871 - Start using ESLint for adblockplusui

ext/background.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
  * 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/>.
  */
 
 "use strict";
 
+(function()
 {
   if (typeof ext == "undefined")
     window.ext = {};
 
   window.addEventListener("load", () =>
   {
     parent.postMessage({
       type: "backgroundPageLoaded"
     }, "*");
   }, false);
 
   function PageMap()
   {
     this._keys = [];
     this._values = [];
   }
   PageMap.prototype = {
     keys()
     {
-      return this._keys.map(source =>
+      return this._keys.map((source) =>
       {
         return new window.ext.Page(source);
       });
     },
 
     get(page)
     {
       return this._values[this._keys.indexOf(page._source)];
     },
 
@@ skipping 33 matching lines @@
       window.open("new-options.html", "_blank");
 
     if (callback)
       callback();
   };
 
   window.ext.devtools = {
     onCreated: {
       addListener(listener)
       {
-        window.addEventListener("message", event =>
+        window.addEventListener("message", (event) =>
         {
           if (event.data.type == "devtools")
             listener(new ext.Page(event.source));
         });
       }
     }
   };
-}
+}());