Upgrading tests with unittest deprecations

tests/html/filereader_test.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library filereader_test;
 import 'package:unittest/unittest.dart';
 import 'package:unittest/html_config.dart';
 import 'dart:html';
 import 'dart:typed_data';
 
 main() {
   useHtmlConfiguration();
 
   test('readAsText', () {
       var reader = new FileReader();
-      reader.onLoad.listen(expectAsync1((event) {
+      reader.onLoad.listen(expectAsync((event) {
         var result = reader.result;
         expect(result, equals('hello world'));
       }));
       reader.readAsText(new Blob(['hello ', 'world']));
   });
 
   test('readAsArrayBuffer', () {
       var reader = new FileReader();
-      reader.onLoad.listen(expectAsync1((event) {
+      reader.onLoad.listen(expectAsync((event) {
         var result = reader.result;
         expect(result is Uint8List, isTrue);
         expect(result, orderedEquals([65, 66, 67]));
       }));
       reader.readAsArrayBuffer(new Blob(['ABC']));
   });
 
   test('readDataUrl', () {
       var reader = new FileReader();
-      reader.onLoad.listen(expectAsync1((event) {
+      reader.onLoad.listen(expectAsync((event) {
         var result = reader.result;
         expect(result is String, isTrue);
         expect(result.startsWith('data:'), isTrue);
       }));
       reader.readAsDataUrl(new Blob(['ABC']));
   });
 
 }