Adding supported checks for touch event.

tests/html/touchevent_test.dart

Index: tests/html/touchevent_test.dart
diff --git a/tests/html/touchevent_test.dart b/tests/html/touchevent_test.dart
new file mode 100644
index 0000000000000000000000000000000000000000..8d90e5b4378cd8d7a7e9dd86ee4c09b3884c33ed
--- /dev/null
+++ b/tests/html/touchevent_test.dart
@@ -0,0 +1,29 @@
+// Copyright (c) 2013, 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 touch_event_test;
+import '../../pkg/unittest/lib/unittest.dart';
+import '../../pkg/unittest/lib/html_individual_config.dart';
+import 'dart:html';
+
+main() {
+  useHtmlIndividualConfiguration();
+
+  group('supported', () {
+    test('supported', () {
+      expect(TouchEvent.supported, true);
+    });
+  });
+
+  group('functional', () {
+    test('unsupported throws', () {
+      var expectation = TouchEvent.supported ? returnsNormally : throws;
+
+      expect(() {
+        var e = new TouchEvent(null, null, null, 'touch');
+        expect(e is TouchEvent, true);
+      }, expectation);
+    });
+  });
+}