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

chrome/browser/resources/settings/passwords_and_forms_page/credit_card_edit_dialog.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-credit-card-edit-dialog' is the dialog that allows
  * editing or creating a credit card entry.
  */
 
 (function() {
@@ skipping 80 matching lines @@
       firstYear = selectedYear;
     else if (selectedYear > lastYear)
       lastYear = selectedYear;
 
     var yearList = [];
     for (var i = firstYear; i <= lastYear; ++i) {
       yearList.push(i.toString());
     }
     this.yearList_ = yearList;
 
-    this.async(function() {
+    this.async(() => {
       this.expirationYear_ = selectedYear.toString();
       this.expirationMonth_ = this.creditCard.expirationMonth;
       this.$.dialog.showModal();
-    }.bind(this));
+    });
   },
 
   /** Closes the dialog. */
   close: function() {
     this.$.dialog.close();
   },
 
   /**
    * Handler for tapping the 'cancel' button. Should just dismiss the dialog.
    * @private
@@ skipping 36 matching lines @@
     this.$.saveButton.disabled = !this.saveEnabled_();
   },
 
   /** @private */
   saveEnabled_: function() {
     return (this.creditCard.name && this.creditCard.name.trim()) ||
         (this.creditCard.cardNumber && this.creditCard.cardNumber.trim());
   },
 });
 })();