MD Settings: Eliminate use of ES6 for Chrome OS

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 135 matching lines @@
       if (selectedDisplay.modes[i].isSelected)
         return i;
     }
     return 0;
   },
 
   /** @private */
   selectedDisplayChanged_: function() {
     // Set |modeValues_| before |selectedModeIndex_| so that the slider updates
     // correctly.
-    let numModes = this.selectedDisplay.modes.length;
+    var numModes = this.selectedDisplay.modes.length;
     if (numModes == 0) {
       this.modeValues_ = [];
       this.selectedModeIndex_ = 0;
       this.currentSelectedModeIndex_ = 0;
       return;
     }
     this.modeValues_ = Array.from(Array(numModes).keys());
     this.selectedModeIndex_ = this.getSelectedModeIndex_(this.selectedDisplay);
     this.currentSelectedModeIndex_ = this.selectedModeIndex_;
   },
@@ skipping 96 matching lines @@
 
   /**
    * @return {string}
    * @private
    */
   getResolutionText_: function() {
     if (this.selectedDisplay.modes.length == 0 ||
         this.currentSelectedModeIndex_ == -1) {
       // If currentSelectedModeIndex_ == -1, selectedDisplay and
       // selectedModeIndex_ are not in sync.
-      let widthStr = this.selectedDisplay.bounds.width.toString();
-      let heightStr = this.selectedDisplay.bounds.height.toString();
-      return this.i18n('displayResolutionText', widthStr, heightStr);
+      return this.i18n(
+          'displayResolutionText', this.selectedDisplay.bounds.width.toString(),
+          this.selectedDisplay.bounds.height.toString());
     }
-    let mode = this.selectedDisplay.modes[this.selectedModeIndex_];
-    let best =
+    var mode = this.selectedDisplay.modes[this.selectedModeIndex_];
+    var best =
         this.selectedDisplay.isInternal ? mode.uiScale == 1.0 : mode.isNative;
-    let widthStr = mode.width.toString();
-    let heightStr = mode.height.toString();
+    var widthStr = mode.width.toString();
+    var heightStr = mode.height.toString();
     if (best)
       return this.i18n('displayResolutionTextBest', widthStr, heightStr);
     else if (mode.isNative)
       return this.i18n('displayResolutionTextNative', widthStr, heightStr);
     return this.i18n('displayResolutionText', widthStr, heightStr);
   },
 
   /**
    * @param {!{detail: string}} e |e.detail| is the id of the selected display.
    * @private
    */
   onSelectDisplay_: function(e) {
     var id = e.detail;
-    for (let display of this.displays) {
+    for (var i = 0; i < this.displays.length; ++i) {
+      var display = this.displays[i];
       if (id != display.id)
         continue;
       this.currentSelectedModeIndex_ = -1;
       this.selectedDisplay = display;
     }
   },
 
   /**
    * Handles event when a display tab is selected.
    * @param {!{detail: !{item: !{displayId: string}}}} e
@@ skipping 54 matching lines @@
     settings.display.systemDisplayApi.setDisplayProperties(
         this.selectedDisplay.id, properties,
         this.setPropertiesCallback_.bind(this));
   },
 
   /**
    * @param {!Event} event
    * @private
    */
   onOrientationChange_: function(event) {
-    let target = /** @type {!HTMLSelectElement} */ (event.target);
+    var target = /** @type {!HTMLSelectElement} */ (event.target);
     /** @type {!chrome.system.display.DisplayProperties} */ var properties = {
       rotation: parseInt(target.value, 10)
     };
     settings.display.systemDisplayApi.setDisplayProperties(
         this.selectedDisplay.id, properties,
         this.setPropertiesCallback_.bind(this));
   },
 
   /** @private */
   onMirroredTap_: function() {
     var id = '';
     /** @type {!chrome.system.display.DisplayProperties} */ var properties = {};
     if (this.isMirrored_(this.displays)) {
       id = this.primaryDisplayId;
       properties.mirroringSourceId = '';
     } else {
       // Set the mirroringSourceId of the secondary (first non-primary) display.
-      for (var display of this.displays) {
+      for (var i = 0; i < this.displays.length; ++i) {
+        var display = this.displays[i];
         if (display.id != this.primaryDisplayId) {
           id = display.id;
           break;
         }
       }
       properties.mirroringSourceId = this.primaryDisplayId;
     }
     settings.display.systemDisplayApi.setDisplayProperties(
         id, properties, this.setPropertiesCallback_.bind(this));
   },
 
   /**
    * @param {!Event} e
    * @private
    */
   onOverscanTap_: function(e) {
     e.preventDefault();
     this.overscanDisplayId = this.selectedDisplay.id;
     this.showOverscanDialog_(true);
   },
 
   /** @private */
   updateDisplayInfo_: function() {
     var displayIds = '';
     var primaryDisplay = undefined;
     var selectedDisplay = undefined;
-    for (var display of this.displays) {
+    for (var i = 0; i < this.displays.length; ++i) {
+      var display = this.displays[i];
       if (displayIds)
         displayIds += ',';
       displayIds += display.id;
       if (display.isPrimary && !primaryDisplay)
         primaryDisplay = display;
       if (this.selectedDisplay && display.id == this.selectedDisplay.id)
         selectedDisplay = display;
     }
     this.displayIds = displayIds;
     this.primaryDisplayId = (primaryDisplay && primaryDisplay.id) || '';
     this.selectedDisplay = selectedDisplay || primaryDisplay ||
         (this.displays && this.displays[0]);
     // Save the selected mode index received from Chrome so that we do not
     // send an unnecessary setDisplayProperties call (which would log an error).
     this.currentSelectedModeIndex_ =
         this.getSelectedModeIndex_(this.selectedDisplay);
 
     this.$.displayLayout.updateDisplays(this.displays, this.layouts);
   },
 
   /** @private */
   setPropertiesCallback_: function() {
     if (chrome.runtime.lastError) {
       console.error(
           'setDisplayProperties Error: ' + chrome.runtime.lastError.message);
     }
   },
 });