diff -r 000000000000 -r 6474c204b198 dom/tests/mochitest/localstorage/interOriginTest2.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/tests/mochitest/localstorage/interOriginTest2.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,53 @@
+var t = async_test(document.title);
+
+var frameLoadsPending = 2;
+
+var callMasterFrame = true;
+var testDone = false;
+
+var masterFrameOrigin = "";
+var slaveFrameOrigin = "";
+
+var failureRegExp = new RegExp("^FAILURE");
+
+const framePath = "/tests/dom/tests/mochitest/localstorage/";
+
+window.addEventListener("message", onMessageReceived, false);
+
+function onMessageReceived(event)
+{
+  switch (event.data)
+  {
+    // Indication of the frame onload event
+    case "frame loaded":
+      if (--frameLoadsPending)
+        break;
+
+      // Just fall through...
+
+    // Indication of successfully finished step of a test
+    case "perf":
+      if (callMasterFrame)
+        masterFrame.postMessage("step", masterFrameOrigin);
+      else
+        slaveFrame.postMessage("step", slaveFrameOrigin);
+      callMasterFrame = !callMasterFrame;
+      break;
+
+    // Indication of all test parts finish (from any of the frames)
+    case "done":
+      if (testDone)
+        break;
+
+      testDone = true;
+      t.done();
+      break;
+
+    // Any other message indicates error, succes or todo message of a test
+    default:
+      t.step(function() {
+        assert_true(!event.data.match(failureRegExp), event.data);
+      });
+      break;
+  }
+}