[MD settings] hide option for incognito on session only exceptions

chrome/browser/resources/settings/site_settings/site_list.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
  * 'site-list' shows a list of Allowed and Blocked sites for a given
  * category.
  */
 Polymer({
@@ skipping 91 matching lines @@
       values: {
         ALLOW: 'Allow',
         BLOCK: 'Block',
         RESET: 'Reset',
         SESSION_ONLY: 'SessionOnly',
       }
     },
   },
 
   /**
-   * The element to return focus to, when the currntly active dialog is closed.
+   * The element to return focus to, when the currently active dialog is closed.
    * @private {?HTMLElement}
    */
   activeDialogAnchor_: null,
 
   observers: ['configureWidget_(category, categorySubtype)'],
 
   ready: function() {
     this.addWebUIListener('contentSettingSitePermissionChanged',
         this.siteWithinCategoryChanged_.bind(this));
     this.addWebUIListener('onIncognitoStatusChanged',
         this.onIncognitoStatusChanged_.bind(this));
   },
 
   /**
    * Called when a site changes permission.
    * @param {string} category The category of the site that changed.
    * @param {string} site The site that changed.
    * @private
    */
   siteWithinCategoryChanged_: function(category, site) {
     if (category == this.category || this.allSites)
       this.configureWidget_();
   },
 
   /**
    * Called for each site list when incognito is enabled or disabled. Only
-   * called on change (opening N incogito windows only fires one message).
+   * called on change (opening N incognito windows only fires one message).
    * Another message is sent when the *last* incognito window closes.
    * @private
    */
   onIncognitoStatusChanged_: function() {
     // The SESSION_ONLY list won't have any incognito exceptions. (Minor
     // optimization, not required).
     if (this.categorySubtype == settings.PermissionValues.SESSION_ONLY)
       return;
 
     // A change notification is not sent for each site. So we repopulate the
@@ skipping 344 matching lines @@
   /** @private */
   closeActionMenu_: function() {
     this.actionMenuSite_ = null;
     this.activeDialogAnchor_ = null;
     var actionMenu = /** @type {!CrActionMenuElement} */ (
         this.$$('dialog[is=cr-action-menu]'));
     if (actionMenu.open)
       actionMenu.close();
   },
 });