Adding test for validating that formdata is sent.

tests/html/form_data_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 FormDataTest;
 
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_config.dart';
 import 'dart:html';
 
+void fail(message) {
+  guardAsync(() {
+    expect(false, isTrue, reason: message);
+  });
+}
+
 void main() {
   // TODO(efortuna): This is a bad test. Revisit when we have tests that can run
   // both a server and fire up a browser.
   useHtmlConfiguration();
 
   var isFormData = predicate((x) => x is FormData, 'is a FormData');
 
   test('constructorTest1', () {
     var form = new FormData();
     expect(form, isNotNull);
@@ skipping 15 matching lines @@
     expect(form, isNotNull);
   });
 
   test('appendBlob', () {
     var form = new FormData();
     var blob = new Blob(
         ['Indescribable... Indestructible! Nothing can stop it!'],
         'text/plain');
     form.append('theBlob', blob, 'theBlob.txt');
   });
+
+  test('send', () {
+    var form = new FormData();
+    var blobString = 'Indescribable... Indestructible! Nothing can stop it!';
+    var blob = new Blob(
+        [blobString],
+        'text/plain');
+    form.append('theBlob', blob, 'theBlob.txt');
+
+    var xhr = new HttpRequest();
+    xhr.open("POST", "http://localhost:9876/echo");
+
+    xhr.on.load.add(expectAsync1((e) {
+      expect(xhr.responseText.contains(blobString), true);
+    }));
+    xhr.on.error.add((e) {
+      fail('$e');
+    });
+    xhr.send(form);
+  });
 }