Issue 6449 - Switch to Harmony modules

lib/prefs.js

Index: lib/prefs.js
===================================================================
--- a/lib/prefs.js
+++ b/lib/prefs.js
@@ -12,19 +12,17 @@
  * 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/>.
  */
 
 /** @module prefs */
 
-"use strict";
-
-const {EventEmitter} = require("events");
+import {EventEmitter} from "events";
 
 const keyPrefix = "pref:";
 
 let eventEmitter = new EventEmitter();
 let overrides = Object.create(null);
 
 /** @lends module:prefs.Prefs */
 let defaults = Object.create(null);
@@ -207,17 +205,17 @@
  * @type {number}
  */
 defaults.last_updates_page_displayed = 0;
 
 /**
   * @namespace
   * @static
   */
-let Prefs = exports.Prefs = {
+export const Prefs = {
   /**
    * Adds a callback that is called when the
    * value of a specified preference changed.
    *
    * @param {string}   preference
    * @param {function} callback
    */
   on(preference, callback)