MD Settings: Device: fix initialization

chrome/browser/resources/settings/device_page/device_page.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-device-page' is the settings page for device and
  * peripheral settings.
  */
 Polymer({
   is: 'settings-device-page',
 
   behaviors: [
     I18nBehavior,
     WebUIListenerBehavior,
     settings.RouteObserverBehavior,
   ],
 
   properties: {
     prefs: {
       type: Object,
       notify: true,
     },
 
     /**
-     * |hasMouse_|, |hasTouchpad_|, and |hasStylus_| start undefined so
-     * observers don't trigger until they have been populated.
+     * |hasMouse_| and |hasTouchpad_| start undefined so observers don't trigger
+     * until they have been populated.
      * @private
      */
-    hasMouse_: {
-      type: Boolean,
-      value: false
-    },
+    hasMouse_: Boolean,
 
     /** @private */
-    hasTouchpad_: {
-      type: Boolean,
-      value: false
-    },
+    hasTouchpad_: Boolean,
 
-    /** @private */
+    /**
+     * |hasStylus_| is initialized to false so that dom-if behaves correctly.
+     * @private
+     */
     hasStylus_: {
       type: Boolean,
-      value: false
+      value: false,
     },
 
     /**
      * Whether power status and settings should be fetched and displayed.
      * @private
      */
     enablePowerSettings_: {
       type: Boolean,
       value: function() {
         return loadTimeData.getBoolean('enablePowerSettings');
@@ skipping 109 matching lines @@
       return source.type == settings.PowerDeviceType.DUAL_ROLE_USB;
     });
   },
 
   /**
    * @param {!Array<!settings.PowerSource>} powerSources
    * @param {boolean} lowPowerCharger
    * @return {string} Description of the power source.
    * @private
    */
-  computePowerSourceName_: function (powerSources, lowPowerCharger) {
+  computePowerSourceName_: function(powerSources, lowPowerCharger) {
     if (lowPowerCharger)
       return this.i18n('powerSourceLowPowerCharger');
     if (powerSources.length)
       return this.i18n('powerSourceAcAdapter');
     return '';
   },
 
   /**
    * Handler for tapping the mouse and touchpad settings menu item.
    * @private
@@ skipping 72 matching lines @@
    * @private
    */
   checkPointerSubpage_: function() {
     // Check that the properties have explicitly been set to false.
     if (this.hasMouse_ === false && this.hasTouchpad_ === false &&
         settings.getCurrentRoute() == settings.Route.POINTERS) {
       settings.navigateTo(settings.Route.DEVICE);
     }
   },
 });