[MD settings] adding dom-if to hide homepage settings

chrome/browser/resources/settings/appearance_page/appearance_page.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.
 
 /**
  * 'cr-settings-appearance-page' is the settings page containing appearance
  * settings.
  *
  * Example:
  *
@@ skipping 11 matching lines @@
 
   properties: {
     /**
      * Preferences state.
      */
     prefs: {
       type: Object,
       notify: true,
     },
 
+    i18n_: {
+      type: Object,
+      value: function() {
+        return {
+          homePageNtp: loadTimeData.getString('homePageNtp'),
+          openThisPage: loadTimeData.getString('openThisPage'),
+        };
+      },
+    },
+
     // prefs.homepage_is_newtabpage.value
     isNewTabPageString_: {
       type: String,
       notify: true,
       observer: 'isNewTabPageStringChanged_',
     }
   },
 
   observers: [
     'homepageIsNewTabPageChanged_(prefs.homepage_is_newtabpage.value)',
@@ skipping 28 matching lines @@
   /** @private */
   openThemesGallery_: function() {
     window.open(loadTimeData.getString('themesGalleryUrl'));
   },
 
   /** @private */
   resetTheme_: function() {
     chrome.send('resetTheme');
   },
 });