diff -r 000000000000 -r 6474c204b198 dom/workers/test/closeOnGC_worker.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/workers/test/closeOnGC_worker.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,11 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+onclose = function() {
+  var xhr = new XMLHttpRequest();
+  xhr.open("POST", "closeOnGC_server.sjs" + location.search, false);
+  xhr.send();
+};
+
+postMessage("ready");