MD Settings: Eliminate use of ES6 for Chrome OS

chrome/browser/resources/settings/internet_page/network_summary_item.js

 // Copyright 2015 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 Polymer element for displaying the network state for a specific
  * type and a list of networks for that type.
  */
 
 /** @typedef {chrome.networkingPrivate.DeviceStateProperties} */
@@ skipping 86 matching lines @@
     return !!this.expanded_ && !!this.deviceState.Scanning;
   },
 
   /**
    * Show the <network-siminfo> element if this is a disabled and locked
    * cellular device.
    * @return {boolean}
    * @private
    */
   showSimInfo_: function() {
-    let device = this.deviceState;
+    var device = this.deviceState;
     if (device.Type != CrOnc.Type.CELLULAR ||
         this.deviceIsEnabled_(this.deviceState)) {
       return false;
     }
     return device.SimPresent === false ||
         device.SimLockType == CrOnc.LockType.PIN ||
         device.SimLockType == CrOnc.LockType.PUK;
   },
 
   /**
@@ skipping 76 matching lines @@
         chrome.networkingPrivate.DeviceStateType.PROHIBITED;
   },
 
   /**
    * @return {boolean} Whether or not to show the UI to expand the list.
    * @private
    */
   expandIsVisible_: function() {
     if (!this.deviceIsEnabled_(this.deviceState))
       return false;
-    let type = this.deviceState.Type;
+    var type = this.deviceState.Type;
     var minLength =
         (type == CrOnc.Type.WI_FI || type == CrOnc.Type.VPN) ? 1 : 2;
     return this.networkStateList.length >= minLength;
   },
 
   /**
    * @return {boolean} Whether or not to show the UI to show details.
    * @private
    */
   showDetailsIsVisible_: function() {
@@ skipping 57 matching lines @@
    */
   onDeviceEnabledTap_: function(event) {
     var deviceIsEnabled = this.deviceIsEnabled_(this.deviceState);
     var type = this.deviceState ? this.deviceState.Type : '';
     this.fire(
         'device-enabled-toggled', {enabled: !deviceIsEnabled, type: type});
     // Make sure this does not propagate to onDetailsTap_.
     event.stopPropagation();
   },
 });