incorporated PR comments

Author: prakhar1989

javascript/widgets/config.js

@@ -299,7 +299,7 @@ firebaseui.auth.widget.Config.prototype.isDisplayNameRequired = function() {
 
   for (var i = 0; i < signInOptions.length; i++) {
     if (signInOptions[i]['provider'] == firebase.auth.EmailAuthProvider.PROVIDER_ID
-        && signInOptions[i]['requireDisplayName'] !== undefined) {
+        && typeof signInOptions[i]['requireDisplayName'] !== 'undefined') {
       return /** @type {boolean} */ (!!signInOptions[i]['requireDisplayName']);
     }
   }

javascript/widgets/handler/passwordsignup_test.js

@@ -108,8 +108,7 @@ function testHandlePasswordSignUp_withoutDisplayName() {
   testAuth.assertCreateUserWithEmailAndPassword(
       [passwordAccount.getEmail(), '123123'], function() {
         testAuth.setUser({
-          'email': passwordAccount.getEmail(),
-          'displayName': passwordAccount.getDisplayName()
+          'email': passwordAccount.getEmail()
         });
         return testAuth.currentUser;
       });