Fix SendPortSync dispatch for FF

lib/html/src/Isolates.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.
 
 _serialize(var message) {
   return new _JsSerializer().traverse(message);
 }
 
 class _JsSerializer extends _Serializer {
 
@@ skipping 71 matching lines @@
     var result = _call(_isolateId, _portId, serialized);
     return _deserialize(result);
   }
 
   static _call(int isolateId, int portId, var message) {
     var target = 'dart-port-$isolateId-$portId'; 
     // TODO(vsm): Make this re-entrant.
     // TODO(vsm): Set this up set once, on the first call.
     var source = '$target-result';
     var result = null;
-    var listener = (TextEvent e) {
-      result = JSON.parse(e.data);
+    var listener = (Event e) {
+      result = JSON.parse(_getPortSyncEventData(e));
     };
     window.on[source].add(listener);
     _dispatchEvent(target, [source, message]);
     window.on[source].remove(listener);
     return result;
   }
 }
 
 // The receiver is in the same Dart isolate, compiled to JS.
 class _LocalSendPortSync implements SendPortSync {
@@ skipping 50 matching lines @@
     return _cachedIsolateId;
   }
 
   static String _getListenerName(isolateId, portId) =>
       'dart-port-$isolateId-$portId'; 
   String get _listenerName => _getListenerName(_isolateId, _portId);
 
   void receive(callback(var message)) {
     _callback = callback;
     if (_listener === null) {
-      _listener = (TextEvent e) {
-        var data = JSON.parse(e.data);
+      _listener = (Event e) {
+        var data = JSON.parse(_getPortSyncEventData(e));
         var replyTo = data[0];
         var message = _deserialize(data[1]);
         var result = _callback(message);
         _dispatchEvent(replyTo, _serialize(result));
       };
       window.on[_listenerName].add(_listener);
     }
   }
 
   void close() {
@@ skipping 10 matching lines @@
       return _portMap[portId].toSendPort();
     } else {
       return new _RemoteSendPortSync(isolateId, portId);
     }
   }
 }
 
 get _isolateId => ReceivePortSync._isolateId;
 
 void _dispatchEvent(String receiver, var message) {
-  var event = document.$dom_createEvent('TextEvent');
-  event.initTextEvent(receiver, false, false, window, JSON.stringify(message));
+  var event = document.$dom_createEvent('CustomEvent');
+  event.initCustomEvent(receiver, false, false, JSON.stringify(message));
   window.$dom_dispatchEvent(event);
 }
+
+String _getPortSyncEventData(CustomEvent event) => event.detail;