Issue 6972 - Use Buffer.from in tests

test/_common.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 25 matching lines @@
     addObserver() {}
   }
 };
 let XPCOMUtils = {
   generateQI() {}
 };
 let FileUtils = {};
 let resources = {Services, XPCOMUtils, FileUtils};
 
 let globals = {
-  atob: data => new Buffer(data, "base64").toString("binary"),
-  btoa: data => new Buffer(data, "binary").toString("base64"),
+  atob: data => Buffer.from(data, "base64").toString("binary"),
+  btoa: data => Buffer.from(data, "binary").toString("base64"),
   Ci: {
   },
   Cu: {
     import(resource)
     {
       let match = /^resource:\/\/gre\/modules\/(.+)\.jsm$/.exec(resource);
       let resourceName = match && match[1];
       if (resourceName && resources.hasOwnProperty(resourceName))
         return {[resourceName]: resources[resourceName]};
 
@@ skipping 347 matching lines @@
       }
     })
   };
 };
 
 exports.unexpectedError = function(error)
 {
   console.error(error);
   this.ok(false, "Unexpected error: " + error);
 };