Print Preview: Make getChildElement return required HTMLElement

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

 // Copyright 2014 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';
 
   /**
    * Print options section to control printer advanced options.
    * @param {!print_preview.ticket_items.VendorItems} ticketItem Ticket item to
@@ skipping 63 matching lines @@
           print_preview.DestinationStore.EventType.
               SELECTED_DESTINATION_CAPABILITIES_READY,
           this.onDestinationChanged_.bind(this));
     },
 
     /**
      * @return {!HTMLElement}
      * @private
      */
     getButton_: function() {
-      return assert(this.getChildElement('.advanced-options-settings-button'));
+      return this.getChildElement('.advanced-options-settings-button');
     },
 
     /**
      * Called when the destination selection has changed. Updates UI elements.
      * @private
      */
     onDestinationChanged_: function() {
       this.updateUiStateInternal();
     }
   };
 
   // Export
   return {
     AdvancedOptionsSettings: AdvancedOptionsSettings
   };
 });