[MD settings] theme name shown in sub-label, wallpaper chrome os only

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.
 
 /**
  * 'settings-appearance-page' is the settings page containing appearance
  * settings.
  *
  * Example:
  *
  *    <iron-animated-pages>
  *      <settings-appearance-page prefs="{{prefs}}">
  *      </settings-appearance-page>
  *      ... other pages ...
  *    </iron-animated-pages>
  */
 Polymer({
   is: 'settings-appearance-page',
 
+  behaviors: [I18nBehavior],
+
   properties: {
     /**
      * The current active route.
      */
     currentRoute: {
       notify: true,
       type: Object,
     },
 
     /**
@@ skipping 62 matching lines @@
         {value: 110, name: '110%'},
         {value: 125, name: '125%'},
         {value: 150, name: '150%'},
         {value: 175, name: '175%'},
         {value: 200, name: '200%'},
         {value: 300, name: '300%'},
         {value: 400, name: '400%'},
         {value: 500, name: '500%'},
       ],
     },
+
+    /** @private */
+    themeSublabel_: String,
   },
 
-  behaviors: [
-    I18nBehavior,
-  ],
-
   observers: [
+    'themeChanged_(prefs.extensions.theme.id.value)',
     'zoomLevelChanged_(defaultZoomLevel_.value)',
   ],
 
   ready: function() {
     this.$.defaultFontSize.menuOptions = this.fontSizeOptions_;
     this.$.pageZoom.menuOptions = this.pageZoomOptions_;
     // TODO(dschuyler): Look into adding a listener for the
     // default zoom percent.
     chrome.settingsPrivate.getDefaultZoomPercent(
         this.zoomPrefChanged_.bind(this));
@@ skipping 43 matching lines @@
   resetTheme_: function() {
     chrome.send('resetTheme');
   },
 
   /** @private */
   showFontsPage_: function() {
     return this.currentRoute.subpage[0] == 'appearance-fonts';
   },
 
   /**
+   * @param {string} themeId The theme ID.
+   * @private
+   */
+  themeChanged_: function(themeId) {
+    if (themeId) {
+      chrome.management.get(themeId,
+          function(info) {
+            this.themeSublabel_ = info.name;
+          }.bind(this));
+    } else {
+      this.themeSublabel_ = this.i18n('chooseFromWebStore');
+    }
+  },
+
+  /**
    * @param {number} percent The integer percentage of the page zoom.
    * @private
    */
   zoomPrefChanged_: function(percent) {
     this.set('defaultZoomLevel_.value', percent);
   },
 
   /**
    * @param {number} percent The integer percentage of the page zoom.
    * @private
    */
   zoomLevelChanged_: function(percent) {
     // The |percent| may be undefined on startup.
     if (percent === undefined)
       return;
     chrome.settingsPrivate.setDefaultZoomPercent(percent);
   },
 });