Add unhandledExceptionCallback to streamSpawnFunction.

runtime/lib/isolate_patch.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.
 
 patch class ReceivePort {
   /* patch */ factory ReceivePort() {
     return new _ReceivePortImpl();
   }
 }
 
@@ skipping 113 matching lines @@
 
 patch class _Isolate {
   /* patch */ static ReceivePort get port {
     if (_portInternal == null) {
       _portInternal = _getPortInternal();
     }
     return _portInternal;
   }
 
   /* patch */ static spawnFunction(void topLevelFunction(),
-      [bool UnhandledExceptionCallback(IsolateUnhandledException e)]) 
+      [bool unhandledExceptionCallback(IsolateUnhandledException e)])
       native "isolate_spawnFunction";
 
   /* patch */ static spawnUri(String uri) native "isolate_spawnUri";
 }