Fix SendPortSync dispatch for FF

client/dart.js

Index: client/dart.js
diff --git a/client/dart.js b/client/dart.js
index 094122a2537797fa7a69b2d4f5b7c7998c19d2d2..c76e3fa5fad0d02620f7b0050b640179aa8c314a 100644
--- a/client/dart.js
+++ b/client/dart.js
@@ -191,7 +191,7 @@ function ReceivePortSync() {
 
   if (navigator.webkitStartDart) {
     window.addEventListener('js-sync-message', function(event) {
-      var data = JSON.parse(event.data);
+      var data = JSON.parse(getPortSyncEventData(event));
       var deserialized = deserialize(data.message);
       var result = ReceivePortSync.map[data.id].callback(deserialized);
       // TODO(vsm): Handle and propagate exceptions.
@@ -220,11 +220,15 @@ function ReceivePortSync() {
 
   function dispatchEvent(receiver, message) {
     var string = JSON.stringify(message);
-    var event = document.createEvent('TextEvent');
-    event.initTextEvent(receiver, false, false, window, string);
+    var event = document.createEvent('CustomEvent');
+    event.initCustomEvent(receiver, false, false, string);
     window.dispatchEvent(event);
   }
 
+  function getPortSyncEventData(event) {
+    return event.detail;
+  }
+
   DartSendPortSync.prototype.callSync = function(message) {
     var serialized = serialize(message);
     var target = 'dart-port-' + this.isolateId + '-' + this.portId;
@@ -233,7 +237,7 @@ function ReceivePortSync() {
     var source = target + '-result';
     var result = null;
     var listener = function (e) {
-      result = JSON.parse(e.data);
+      result = JSON.parse(getPortSyncEventData(e));
     };
     window.addEventListener(source, listener, false);
     dispatchEvent(target, [source, serialized]);