Site Settings: Give each category its own route.

chrome/browser/resources/settings/site_settings/constants.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.define('settings', function() {
   /**
    * The possible contentSettingsTypes (the ones we currently support
    * configuring in the UI). This is a subset of the constants found under
    * content_setttings_types.h and the values should be kept in sync.
    * TODO(finnur): When all categories have been implemented we can just
    * generate these constants from content_setttings_types.h.
    * @enum {number}
    */
   var ContentSettingsTypes = {
     COOKIES: 0,
     IMAGES: 1,
     JAVASCRIPT: 2,
     POPUPS: 4,
     GEOLOCATION: 5,
-    NOTIFICATION: 6,
+    NOTIFICATIONS: 6,
     FULLSCREEN: 8,
     MIC: 12,
     CAMERA: 13,
   };
 
   /**
    * Contains the possible values for a given contentSettingsType.
    * @enum {number}
    */
   var PermissionValues = {
     ALLOW: 1,
     BLOCK: 2,
     ASK: 3,
   };
 
   return {
     ContentSettingsTypes: ContentSettingsTypes,
     PermissionValues: PermissionValues,
   };
 });