MD Settings: Convert all usages of .bind(this) to use ES6 arrow function.

chrome/browser/resources/settings/about_page/about_page_browser_proxy.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 A helper object used from the "About" section to interact with
  * the browser.
  */
 
 // <if expr="chromeos">
 /**
  * @typedef {{
  *   text: string,
  *   url: string,
  * }}
  */
 var RegulatoryInfo;
 
 /**
  * @typedef {{
- *   currentChannel: string,
- *   targetChannel: string,
+ *   currentChannel: BrowserChannel,
+ *   targetChannel: BrowserChannel,
  *   canChangeChannel: boolean,
  * }}
  */
 var ChannelInfo;
 
 /**
  * @typedef {{
  *   arcVersion: string,
  *   osFirmware: string,
  *   osVersion: string,
@@ skipping 233 matching lines @@
 
   cr.addSingletonGetter(AboutPageBrowserProxyImpl);
 
   return {
     AboutPageBrowserProxy: AboutPageBrowserProxy,
     AboutPageBrowserProxyImpl: AboutPageBrowserProxyImpl,
     browserChannelToI18nId: browserChannelToI18nId,
     isTargetChannelMoreStable: isTargetChannelMoreStable,
   };
 });