diff -r 000000000000 -r 6474c204b198 dom/workers/test/xpcshell/test_workers.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/workers/test/xpcshell/test_workers.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,44 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+Components.utils.import("resource://gre/modules/Promise.jsm");
+
+// Worker must be loaded from a chrome:// uri, not a file://
+// uri, so we first need to load it.
+let WORKER_SOURCE_URI = "chrome://workers/content/worker.js";
+do_load_manifest("data/chrome.manifest");
+
+function run_test() {
+  run_next_test();
+}
+
+function talk_with_worker(worker) {
+  let deferred = Promise.defer();
+  worker.onmessage = function(event) {
+    let success = true;
+    if (event.data == "OK") {
+      deferred.resolve();
+    } else {
+      success = false;
+      deferred.reject(event);
+    }
+    do_check_true(success);
+    worker.terminate();
+  };
+  worker.onerror = function(event) {
+    let error = new Error(event.message, event.filename, event.lineno);
+    worker.terminate();
+    deferred.reject(error);
+  };
+  worker.postMessage("START");
+  return deferred.promise;
+}
+
+
+add_task(function test_chrome_worker() {
+  return talk_with_worker(new ChromeWorker(WORKER_SOURCE_URI));
+});
+
+add_task(function test_worker() {
+  return talk_with_worker(new Worker(WORKER_SOURCE_URI));
+});