diff -r 000000000000 -r 6474c204b198 toolkit/components/satchel/test/browser/head.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/toolkit/components/satchel/test/browser/head.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,8 @@
+
+function whenNewWindowLoaded(aOptions, aCallback) {
+  let win = OpenBrowserWindow(aOptions);
+  win.addEventListener("load", function onLoad() {
+    win.removeEventListener("load", onLoad, false);
+    aCallback(win);
+  }, false);
+}