Initial tests for JS interop

tests/html/js_interop_2_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('JsInterop2Test');
+#import('../../lib/unittest/unittest.dart');
+#import('../../lib/unittest/html_config.dart');
+#import('dart:html');
+#import('dart:json');
+
+injectSource(code) {
+  final script = new ScriptElement();
+  script.type = 'text/javascript';
+  script.innerHTML = code;
+  document.body.nodes.add(script);
+}
+
+isolateTest = """
+  function test(data) {
+    if (data == 'sent')
+      return 'received';
+  }
+
+  var port = new ReceivePortSync(test);
+  window.registerPort('test', port.toSendPort());
+""";
+
+main() {
+  useHtmlConfiguration();
+  var callback;
+  test('dart.js', () {
+    callback = expectAsync1((e) {
+      Expect.isTrue(e.data);
+      window.on.message.remove(callback);
+    });
+    window.on.message.add(callback);
+    injectSource(@"window.postMessage(window._$dart$initialized, '*');");
+  });
+
+  test('isolateTest', () {
+      injectSource(isolateTest);
+
+      var port = window.lookupPort('test');
+      var result = port.call('sent');
+      Expect.equals('received', result);
+
+      result = port.call('ignore');
+      Expect.isNull(result);
+  });  
+}