diff -r 000000000000 -r 6474c204b198 ipc/testshell/tests/test_ipcshell_child.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ipc/testshell/tests/test_ipcshell_child.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,9 @@
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+
+const runtime = Cc["@mozilla.org/xre/app-info;1"].getService(Ci.nsIXULRuntime);
+
+if (typeof(run_test) == "undefined") {
+  run_test = function() {
+    do_check_eq(runtime.processType, Ci.nsIXULRuntime.PROCESS_TYPE_DEFAULT);
+  }
}