Dart2js: Fix object leaking between isolates.

sdk/lib/_internal/lib/isolate_helper.dart

Index: sdk/lib/_internal/lib/isolate_helper.dart
diff --git a/sdk/lib/_internal/lib/isolate_helper.dart b/sdk/lib/_internal/lib/isolate_helper.dart
index 0a6bcb7799490c662b794787f17bb8d86587f804..cfb0a96d6b29e04db6760038aad96a41cd24c736 100644
--- a/sdk/lib/_internal/lib/isolate_helper.dart
+++ b/sdk/lib/_internal/lib/isolate_helper.dart
@@ -956,6 +956,8 @@ class IsolateNatives {
       throw new UnsupportedError(
           "Currently spawnUri is not supported without web workers.");
     }
+    message = _serializeMessage(message);
+    args = _serializeMessage(args);  // Or just args.toList() ?

[floitsch, 2014/05/22 09:43:09]

We can't just write `toList()` unless we verify that all of the entries are
Strings.
Maybe we should do that?

[Lasse Reichstein Nielsen, 2014/05/22 11:11:24]

A good idea for another CL.

     _globalState.topEventLoop.enqueue(new _IsolateContext(), () {
       final func = _getJSFunctionFromName(functionName);
       _startIsolate(func, args, message, isSpawnUri, startPaused, replyPort);