Issue 5028 - Use browser namespace

lib/options.js

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-present 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 19 matching lines @@
 {
   browser.tabs.query({}, tabs =>
   {
     // We find a tab ourselves because Edge has a bug when quering tabs with
     // extension URL protocol:
     // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/8094141/
     // https://developer.microsoft.com/en-us/microsoft-edge/platform/issues/8604703/
     // Firefox won't let us query for moz-extension:// pages either, though
     // starting with Firefox 56 an extension can query for its own URLs:
     // https://bugzilla.mozilla.org/show_bug.cgi?id=1271354
-    let fullOptionsUrl = ext.getURL(optionsUrl);
+    let fullOptionsUrl = browser.extension.getURL(optionsUrl);
     callback(tabs.find(element => element.url == fullOptionsUrl));
   });
 }
 
 function returnShowOptionsCall(optionsTab, callback)
 {
   if (!callback)
     return;
 
   if (optionsTab)
@@ skipping 92 matching lines @@
         args: [
           {
             host: getDecodedHostname(currentPage.url).replace(/^www\./, ""),
             whitelisted: !!checkWhitelisted(currentPage)
           }
         ]
       });
     });
   });
 });