Provide a constructor for (DOM)FormData, and rename to the more standard name,

tests/html/form_data_test.dart

Index: tests/html/form_data_test.dart
===================================================================
--- tests/html/form_data_test.dart	(revision 0)
+++ tests/html/form_data_test.dart	(revision 0)
@@ -0,0 +1,36 @@
+// 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/unittest.dart');
+#import('../../pkg/unittest/html_config.dart');
+#import('dart:html');
+
+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();
+
+  test('constructorTest1', () {
+    var form = new FormData();
+    expect(form, isNotNull);
+    expect(form is FormData);
+  });
+
+  test('constructorTest2', () {
+    var form = new FormData(new FormElement());
+    expect(form, isNotNull);
+    expect(form is FormData);
+  });
+
+  test('appendTest', () {
+    var form = new FormData();
+    form.append('test', '1', 'foo');
+    form.append('username', 'Elmo', 'foo');
+    form.append('address', '1 Sesame Street', 'foo');
+    form.append('password', '123456', 'foo');
+    expect(form, isNotNull);
+  });
+}