MD Settings: Remove some ES6 leftovers from CrOS code that break uglify.

chrome/browser/resources/settings/device_page/display.js

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 /**
  * @fileoverview
  * 'settings-display' is the settings subpage for display settings.
  */
 
 cr.define('settings.display', function() {
@@ skipping 100 matching lines @@
   /** @private */
   getDisplayInfo_: function() {
     settings.display.systemDisplayApi.getInfo(
         this.displayInfoFetched_.bind(this));
   },
 
   /**
    * @param {!Array<!chrome.system.display.DisplayUnitInfo>} displays
    * @private
    */
-  displayInfoFetched_(displays) {
+  displayInfoFetched_: function(displays) {
     if (!displays.length)
       return;
     settings.display.systemDisplayApi.getDisplayLayout(
         this.displayLayoutFetched_.bind(this, displays));
   },
 
   /**
    * @param {!Array<!chrome.system.display.DisplayUnitInfo>} displays
    * @param {!Array<!chrome.system.display.DisplayLayout>} layouts
    * @private
    */
-  displayLayoutFetched_(displays, layouts) {
+  displayLayoutFetched_: function(displays, layouts) {
     this.layouts = layouts;
     this.displays = displays;
     this.updateDisplayInfo_();
   },
 
   /**
    * @param {!chrome.system.display.DisplayUnitInfo} selectedDisplay
    * @return {number}
    * @private
    */
@@ skipping 293 matching lines @@
   },
 
   /** @private */
   setPropertiesCallback_: function() {
     if (chrome.runtime.lastError) {
       console.error(
           'setDisplayProperties Error: ' + chrome.runtime.lastError.message);
     }
   },
 });