MD Settings: Remove some unhelpful properties

chrome/browser/resources/settings/about_page/about_page.js

 // Copyright 2016 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 'settings-about-page' contains version and OS related
  * information.
  */
 Polymer({
   is: 'settings-about-page',
@@ skipping 37 matching lines @@
       },
     },
   },
 
   /** @private {?settings.AboutPageBrowserProxy} */
   aboutBrowserProxy_: null,
 
   /** @private {?settings.LifetimeBrowserProxy} */
   lifetimeBrowserProxy_: null,
 
-  /**
-   * @type {string} Selector to get the sections.
-   * TODO(michaelpg): replace duplicate docs with @override once b/24294625
-   * is fixed.
-   */
-  sectionSelector: 'settings-section',
-
   /** @override */
   attached: function() {
     this.aboutBrowserProxy_ = settings.AboutPageBrowserProxyImpl.getInstance();
     this.aboutBrowserProxy_.pageReady();
 
     this.lifetimeBrowserProxy_ =
         settings.LifetimeBrowserProxyImpl.getInstance();
 
 <if expr="chromeos">
     this.addEventListener('target-channel-changed', function(e) {
@@ skipping 216 matching lines @@
   },
 </if>
 
 <if expr="_google_chrome">
   /** @private */
   onReportIssueTap_: function() {
     this.aboutBrowserProxy_.openFeedbackDialog();
   },
 </if>
 });