MD Settings: Eliminate use of ES6 for Chrome OS

chrome/browser/resources/settings/internet_page/network_apnlist.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 and modifying a list of cellular
  * access points.
  */
 Polymer({
   is: 'network-apnlist',
@@ skipping 163 matching lines @@
     return /** @type {!Array<!CrOnc.APNProperties>} */ (
         CrOnc.getActiveValue(apnlist));
   },
 
   /**
    * Event triggered when the selectApn selection changes.
    * @param {!Event} event
    * @private
    */
   onSelectApnChange_: function(event) {
-    let target = /** @type {!HTMLSelectElement} */(event.target);
+    var target = /** @type {!HTMLSelectElement} */(event.target);
     var accessPointName = target.value;
     // When selecting 'Other', don't set a change event unless a valid
     // non-default value has been set for Other.
     if (this.isOtherSelected_(accessPointName) &&
         (!this.otherApn_ || !this.otherApn_.AccessPointName ||
          this.otherApn_.AccessPointName == this.DefaultAccessPointName)) {
       this.selectedApn_ = accessPointName;
       return;
     }
     this.sendApnChange_(accessPointName);
@@ skipping 60 matching lines @@
   },
 
   /**
    * @param {!Array<!CrOnc.APNProperties>} apnList
    * @param {string} accessPointName
    * @return {CrOnc.APNProperties|undefined} The entry in |apnList| matching
    *     |accessPointName| if it exists, or undefined.
    * @private
    */
   findApnInList: function(apnList, accessPointName) {
-    for (let a of apnList) {
-      if (a.AccessPointName == accessPointName)
-        return a;
-    }
-    return undefined;
+    return apnList.find(function(a) {
+      return a.AccessPointName == accessPointName;
+    });
   }
 });