Remove AsyncError with Expando.

tests/html/xhr_test.dart

 // Copyright (c) 2012, 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 XHRTest;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_individual_config.dart';
 import 'dart:async';
 import 'dart:html';
 import 'dart:json' as json;
@@ skipping 68 matching lines @@
 
       xhr.onLoadEnd.listen((ProgressEvent e) {
         loadEndCalled = true;
       });
       xhr.send();
     });
 
     test('XHR.request No file', () {
       HttpRequest.request('NonExistingFile').then(
         (_) { fail('Request should not have succeeded.'); },
-        onError: expectAsync1((e) {
-          var xhr = e.error.target;
+        onError: expectAsync1((error) {
+          var xhr = error.target;
           expect(xhr.readyState, equals(HttpRequest.DONE));
           validate404(xhr);
         }));
     });
 
     test('XHR.request file', () {
       HttpRequest.request(url).then(expectAsync1((xhr) {
         expect(xhr.readyState, equals(HttpRequest.DONE));
         validate200Response(xhr);
       }));
     });
 
     test('XHR.request onProgress', () {
       var progressCalled = false;
       HttpRequest.request(url,
         onProgress: (_) {
           progressCalled = true;
         }).then(expectAsync1(
           (xhr) {
             expect(xhr.readyState, equals(HttpRequest.DONE));
             expect(progressCalled, HttpRequest.supportsProgressEvent);
             validate200Response(xhr);
           }));
     });
 
     test('XHR.request withCredentials No file', () {
       HttpRequest.request('NonExistingFile', withCredentials: true).then(
         (_) { fail('Request should not have succeeded.'); },
-        onError: expectAsync1((e) {
-          var xhr = e.error.target;
+        onError: expectAsync1((error) {
+          var xhr = error.target;
           expect(xhr.readyState, equals(HttpRequest.DONE));
           validate404(xhr);
         }));
     });
 
     test('XHR.request withCredentials file', () {
       HttpRequest.request(url, withCredentials: true).then(expectAsync1((xhr) {
         expect(xhr.readyState, equals(HttpRequest.DONE));
         validate200Response(xhr);
       }));
     });
 
     test('XHR.getString file', () {
       HttpRequest.getString(url).then(expectAsync1((str) {}));
     });
 
     test('XHR.getString No file', () {
       HttpRequest.getString('NonExistingFile').then(
         (_) { fail('Succeeded for non-existing file.'); },
-        onError: expectAsync1((e) {
-          validate404(e.error.target);
+        onError: expectAsync1((error) {
+          validate404(error.target);
         }));
     });
 
     test('XHR.request responseType arraybuffer', () {
       if (ArrayBuffer.supported) {
         HttpRequest.request(url, responseType: 'arraybuffer').then(
           expectAsync1((xhr) {
             expect(xhr.status, equals(200));
             var arrayBuffer = xhr.response;
             expect(arrayBuffer, new isInstanceOf<ArrayBuffer>());
@@ skipping 19 matching lines @@
           (xhr) {
             expect(xhr.status, equals(200));
             var blob = xhr.response;
             expect(blob is Blob, isTrue);
             expect(blob, isNotNull);
           });
       }
     });
   });
 }