Print Preview: Make getChildElement return required HTMLElement

chrome/browser/resources/print_preview/settings/layout_settings.js

 // Copyright (c) 2012 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.
 
 cr.define('print_preview', function() {
   'use strict';
 
   /**
    * Creates a LayoutSettings object. This object encapsulates all settings and
    * logic related to layout mode (portrait/landscape).
@@ skipping 28 matching lines @@
 
     /** @override */
     set isEnabled(isEnabled) {
       this.select_.disabled = !isEnabled;
     },
 
     /** @override */
     enterDocument: function() {
       print_preview.SettingsSection.prototype.enterDocument.call(this);
       this.tracker.add(
-          assert(this.select_), 'change', this.onSelectChange_.bind(this));
+          this.select_, 'change', this.onSelectChange_.bind(this));
       this.tracker.add(
           this.landscapeTicketItem_,
           print_preview.ticket_items.TicketItem.EventType.CHANGE,
           this.onLandscapeTicketItemChange_.bind(this));
     },
 
     /**
      * Called when the select element is changed. Updates the print ticket
      * layout selection.
      * @private
      */
     onSelectChange_: function() {
       var select = this.select_;
       var isLandscape =
           select.options[select.selectedIndex].value == 'landscape';
       this.landscapeTicketItem_.updateValue(isLandscape);
     },
 
     /**
-     * @return {HTMLSelectElement} Select element containing the layout options.
+     * @return {!HTMLSelectElement} Select element containing the layout
+     *     options.
      * @private
      */
     get select_() {
-      return /** @type {HTMLSelectElement} */(
+      return /** @type {!HTMLSelectElement} */(

[dpapad, 2017/05/04 23:59:49]

Same here.

           this.getChildElement('.layout-settings-select'));
     },
 
     /**
      * Called when the print ticket store changes state. Updates the state of
      * the radio buttons and hides the setting if necessary.
      * @private
      */
     onLandscapeTicketItemChange_: function() {
       if (this.isAvailable()) {
         var select = this.select_;
         var valueToSelect =
             this.landscapeTicketItem_.getValue() ? 'landscape' : 'portrait';
         for (var i = 0; i < select.options.length; i++) {
           if (select.options[i].value == valueToSelect) {
             select.selectedIndex = i;
             break;
           }
         }
       }
       this.updateUiStateInternal();
     }
   };
 
   // Export
   return {
     LayoutSettings: LayoutSettings
   };
 });