Convert the password prompt to ES6 syntax

web/password_prompt.js

@@ -30,15 +30,11 @@ import { PasswordResponses } from './pdfjs';
  *                                              entry.
  */
 
+class PasswordPrompt {
   /**
- * @class
- */
-var PasswordPrompt = (function PasswordPromptClosure() {
-  /**
-   * @constructs PasswordPrompt
    * @param {PasswordPromptOptions} options
    */
-  function PasswordPrompt(options) {
+  constructor(options) {
     this.overlayName = options.overlayName;
     this.container = options.container;
     this.label = options.label;
@@ -52,19 +48,18 @@ var PasswordPrompt = (function PasswordPromptClosure() {
     // Attach the event listeners.
     this.submitButton.addEventListener('click', this.verify.bind(this));
     this.cancelButton.addEventListener('click', this.close.bind(this));
-    this.input.addEventListener('keydown', function (e) {
+    this.input.addEventListener('keydown', (e) => {
       if (e.keyCode === 13) { // Enter key
         this.verify();
       }
-    }.bind(this));
+    });
 
     OverlayManager.register(this.overlayName, this.container,
                             this.close.bind(this), true);
   }
 
-  PasswordPrompt.prototype = {
-    open: function PasswordPrompt_open() {
-      OverlayManager.open(this.overlayName).then(function () {
+  open() {
+    OverlayManager.open(this.overlayName).then(() => {
       this.input.type = 'password';
       this.input.focus();
 
@@ -77,33 +72,29 @@ var PasswordPrompt = (function PasswordPromptClosure() {
       }
 
       this.label.textContent = promptString;
-      }.bind(this));
-    },
+    });
+  }
 
-    close: function PasswordPrompt_close() {
-      OverlayManager.close(this.overlayName).then(function () {
+  close() {
+    OverlayManager.close(this.overlayName).then(() => {
       this.input.value = '';
       this.input.type = '';
-      }.bind(this));
-    },
+    });
+  }
 
-    verify: function PasswordPrompt_verify() {
+  verify() {
     var password = this.input.value;
     if (password && password.length > 0) {
       this.close();
       return this.updateCallback(password);
     }
-    },
+  }
 
-    setUpdateCallback:
-        function PasswordPrompt_setUpdateCallback(updateCallback, reason) {
+  setUpdateCallback(updateCallback, reason) {
     this.updateCallback = updateCallback;
     this.reason = reason;
   }
-  };
-
-  return PasswordPrompt;
-})();
+}
 
 export {
   PasswordPrompt,