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

chrome/browser/resources/settings/people_page/sync_page.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.
 
 (function() {
 
 /**
  * Names of the radio buttons which allow the user to choose their encryption
  * mechanism.
  * @enum {string}
@@ skipping 199 matching lines @@
     if (!this.syncPrefs.autofillRegistered || !this.syncPrefs.autofillSynced)
       this.set('syncPrefs.paymentsIntegrationEnabled', false);
 
     // Hide the new passphrase box if the sync data has been encrypted.
     if (this.syncPrefs.encryptAllData)
       this.creatingNewPassphrase_ = false;
 
     // Focus the password input box if password is needed to start sync.
     if (this.syncPrefs.passphraseRequired) {
       // Wait for the dom-if templates to render and subpage to become visible.
-      listenOnce(document, 'show-container', function() {
+      listenOnce(document, 'show-container', () => {
         var input = /** @type {!PaperInputElement} */ (
             this.$$('#existingPassphraseInput'));
         input.inputElement.focus();
-      }.bind(this));
+      });
     }
   },
 
   /**
    * Handler for when the sync all data types checkbox is changed.
    * @param {!Event} event
    * @private
    */
   onSyncAllDataTypesChanged_: function(event) {
     if (event.target.checked) {
@@ skipping 203 matching lines @@
   onLearnMoreTap_: function(event) {
     if (event.target.tagName == 'A') {
       // Stop the propagation of events, so that clicking on links inside
       // checkboxes or radio buttons won't change the value.
       event.stopPropagation();
     }
   }
 });
 
 })();