Issue 4795 - Use modern JavaScript syntax

subscriptionLink.postload.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";
 
 if (document instanceof HTMLDocument)
 {
-  document.addEventListener("click", function(event)
+  document.addEventListener("click", event =>
   {
     // Ignore right-clicks
     if (event.button == 2)
       return;
 
     // Ignore simulated clicks.
     if (event.isTrusted == false)
       return;
 
     // Search the link associated with the click
-    var link = event.target;
+    let link = event.target;
     while (!(link instanceof HTMLAnchorElement))
     {
       link = link.parentNode;
 
       if (!link)
         return;
     }
 
     if (link.protocol == "http:" || link.protocol == "https:")
     {
       if (link.host != "subscribe.adblockplus.org" || link.pathname != "/")
         return;
     }
     else if (!/^abp:\/*subscribe\/*\?/i.test(link.href))
       return;
 
     // This is our link - make sure the browser doesn't handle it
     event.preventDefault();
     event.stopPropagation();
 
     // Decode URL parameters
-    var params = link.search.substr(1).split("&");
-    var title = null;
-    var url = null;
-    for (var i = 0; i < params.length; i++)
+    let title = null;
+    let url = null;
+    for (let param of link.search.substr(1).split("&"))
     {
-      var parts = params[i].split("=", 2);
+      let parts = param.split("=", 2);
       if (parts.length != 2 || !/\S/.test(parts[1]))
         continue;
       switch (parts[0])
       {
         case "title":
           title = decodeURIComponent(parts[1]);
           break;
         case "location":
           url = decodeURIComponent(parts[1]);
           break;
@@ skipping 13 matching lines @@
       return;
 
     ext.backgroundPage.sendMessage({
       type: "subscriptions.add",
       title: title,
       url: url,
       confirm: true
     });
   }, true);
 }