[HBD] Update MD SiteSettingsHandler to support 3 modes.

chrome/browser/resources/settings/site_settings/site_settings_behavior.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.
 
 /**
  * @fileoverview Behavior common to Site Settings classes.
  */
 
 /** @polymerBehavior */
 var SiteSettingsBehaviorImpl = {
@@ skipping 414 matching lines @@
   /**
    * Returns the icon to use for a given site.
    * @param {string} site The url of the site to fetch the icon for.
    * @return {string} The background-image style with the favicon.
    * @private
    */
   computeSiteIcon: function(site) {
     var url = this.ensureUrlHasScheme(site);
     return 'background-image: ' + cr.icon.getFaviconImageSet(url);
   },
+
+  /**
+   * Returns true if the passed content setting is considered 'enabled'.
+   * @param {string} category
+   * @param {string} setting
+   * @return {boolean}
+   * @private
+   */
+  computeIsSettingEnabled: function(category, setting) {
+    // FullScreen is Allow vs. Ask.
+    return category == settings.ContentSettingsTypes.FULLSCREEN ?
+        setting != settings.PermissionValues.ASK :
+        setting != settings.PermissionValues.BLOCK;
+  },
 };
 
 /** @polymerBehavior */
 var SiteSettingsBehavior = [SiteSettingsBehaviorImpl];