First experimental steps towards a better story for JS interop.

lib/dom/templates/html/frog/html_frog.darttemplate

 // 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.
 
 // DO NOT EDIT
 // Auto-generated dart:html library.
 
-#library("html");
+#library('html');
+
+#import('dart:isolate');
+#import('dart:json');
 
 $!GENERATED_DART_FILES
 
 #source('../../dom/src/EventListener.dart');
 #source('../../dom/src/KeyLocation.dart');
 #source('../../dom/src/KeyName.dart');
 #source('../../dom/src/ReadyState.dart');
 #source('../../dom/src/_Collections.dart');
 #source('../../dom/src/_XMLHttpRequestUtils.dart');
 #source('../../html/src/IDBOpenDBRequest.dart');
 #source('../../html/src/Measurement.dart');
 #source('../../html/src/shared_FactoryProviders.dart');
 #source('../../html/src/frog_DOMImplementation.dart');
 #source('../../html/src/frog_FactoryProviders.dart');
 #source('../../html/src/frog_IDBKeyRangeFactoryProvider.dart');
 #source('../../html/src/frog_IDBOpenDBRequestImplementation.dart');
 #source('../../html/src/frog_LocationWrapper.dart');
 #source('../../dom/src/frog_TypedArrayFactoryProvider.dart');
 #source('../../html/src/_Testing.dart');
 #source('../../html/src/Device.dart');
 #source('../../dom/src/_ListIterators.dart');
 #source('../../dom/src/_Lists.dart');
+#source('../../isolate/serialization.dart');
 
 
 Window get window() native "return window;";
 _WindowImpl get _window() native "return window;";
 
 Document get document() native "return document;";
 
 _DocumentImpl get _document() native "return document;";
 
 Element query(String selector) => _document.query(selector);
 ElementList queryAll(String selector) => _document.queryAll(selector);
 
 // Workaround for tags like <cite> that lack their own Element subclass --
 // Dart issue 1990.
 class _HTMLElementImpl extends _ElementImpl native "*HTMLElement" {
 }
+
+// TODO(vsm): Move this to a separate Isolates.dart file.
+_serialize(var message) {
+  // TODO(kasperl): Specialize the serializer.
+  return new _Serializer().traverse(message);
+}
+
+_deserialize(var message) {
+  return new _JsDeserializer().deserialize(message);
+}
+
+class _JsDeserializer extends _Deserializer {
+
+  deserializeSendPort(List x) {
+    num id = x[1];
+    return new _JsSendPortSync(id);
+  }
+
+}
+
+class _JsSendPortSync implements SendPortSync {
+
+  num _id;
+  _JsSendPortSync(this._id);
+
+  callSync(var message) {
+    var serialized = _serialize(message);
+    var result = _call(_id, serialized);
+    return _deserialize(result);
+  }
+
+  static _call(num id, var message) native @"""
+    var deserialized = _deserialize(message);
+    var result = ReceivePortSync.map[id].callback(deserialized);
+    return _serialize(result);
+  """;
+
+}