Support dart and js scripts in HTML tests, on dartium.

tests/html/scripts_test_js.js

Index: tests/html/scripts_test_js.js
diff --git a/tests/html/scripts_test_js.js b/tests/html/scripts_test_js.js
new file mode 100644
index 0000000000000000000000000000000000000000..552d4187d0cb34131b81e11b94d33d67ec9bae86
--- /dev/null
+++ b/tests/html/scripts_test_js.js
@@ -0,0 +1,12 @@
+// 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.
+
+window.postMessage('fish', '*');
+
+function delayed() {
+  window.postMessage('cow', '*');  // Unexpected message OK.
+  parent.postMessage('weasel', '*');  // Message to parent OK.
+  window.postMessage('crab', '*');
+}
+setTimeout(delayed, 500);