Don't use ES6 class for AutoUpdater windows class

atom/browser/api/lib/auto-updater/auto-updater-win.js

@@ -4,21 +4,22 @@ const app = require('electron').app;
 const EventEmitter = require('events').EventEmitter;
 const squirrelUpdate = require('./squirrel-update-win');
 
-class AutoUpdater extends EventEmitter {
+function AutoUpdater() {
-  constructor() {
+  EventEmitter.call(this)
-    super();
+}
-  }
 
-  quitAndInstall() {
+require('util').inherits(AutoUpdater, EventEmitter);
+
+AutoUpdater.prototype.quitAndInstall = function() {
   squirrelUpdate.processStart();
   return app.quit();
-  }
+}
 
-  setFeedURL(updateURL) {
+AutoUpdater.prototype.setFeedURL = function(updateURL) {
   return this.updateURL = updateURL;
-  }
+}
 
-  checkForUpdates() {
+AutoUpdater.prototype.checkForUpdates = function() {
   if (!this.updateURL) {
     return this.emitError('Update URL is not set');
   }
@@ -50,13 +51,12 @@ class AutoUpdater extends EventEmitter {
       });
     };
   })(this));
-  }
+}
 
-  // Private: Emit both error object and message, this is to keep compatibility
+// Private: Emit both error object and message, this is to keep compatibility
-  // with Old APIs.
+// with Old APIs.
-  emitError(message) {
+AutoUpdater.prototype.emitError = (message) {
   return this.emit('error', new Error(message), message);
-  }
 }
 
 module.exports = new AutoUpdater;