diff -r 000000000000 -r 6474c204b198 dom/workers/test/extensions/traditional/WorkerTest.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/workers/test/extensions/traditional/WorkerTest.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,132 @@
+/**
+ * Any copyright is dedicated to the Public Domain.
+ * http://creativecommons.org/publicdomain/zero/1.0/
+ */
+
+const Cc = Components.classes;
+const Ci = Components.interfaces;
+const Cu = Components.utils;
+
+Cu.import("resource://gre/modules/Services.jsm");
+Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+
+var gWorkerAndCallback = {
+  _worker: null,
+  _callback: null,
+
+  _ensureStarted: function() {
+    if (!this._worker) {
+      throw new Error("Not yet started!");
+    }
+  },
+
+  start: function() {
+    if (!this._worker) {
+      var file = __LOCATION__.parent.parent;
+      var fileuri = file.isDirectory() ?
+                    Services.io.newFileURI(file) :
+                    Services.io.newURI('jar:' + file.path + '!/', null, null);
+      var resourceName = "worker-test";
+
+      Services.io.getProtocolHandler("resource").
+                  QueryInterface(Ci.nsIResProtocolHandler).
+                  setSubstitution(resourceName, fileuri);
+
+      var worker = new Worker("resource://" + resourceName + "/worker.js");
+      worker.onerror = function(event) {
+        Cu.reportError(event.message);
+        event.preventDefault();
+      };
+
+      this._worker = worker;
+    }
+  },
+
+  stop: function() {
+    if (this._worker) {
+      try {
+        this.terminate();
+      }
+      catch(e) {
+        Cu.reportError(e);
+      }
+      this._worker = null;
+    }
+  },
+
+  set callback(val) {
+    this._ensureStarted();
+    if (val) {
+      var callback = val.QueryInterface(Ci.nsIWorkerTestCallback);
+      if (this.callback != callback) {
+        this._worker.onmessage = function(event) {
+          callback.onmessage(event.data);
+        };
+        this._worker.onerror = function(event) {
+          callback.onerror(event.message);
+          event.preventDefault();
+        };
+        this._callback = callback;
+      }
+    }
+    else {
+      this._worker.onmessage = null;
+      this._worker.onerror = null;
+      this._callback = null;
+    }
+  },
+
+  get callback() {
+    return this._callback;
+  },
+
+  postMessage: function(data) {
+    this._ensureStarted();
+    this._worker.postMessage(data);
+  },
+
+  terminate: function() {
+    this._ensureStarted();
+    this._worker.terminate();
+    this.callback = null;
+  }
+};
+
+function WorkerTest() {
+}
+WorkerTest.prototype = {
+  observe: function(subject, topic, data) {
+    switch(topic) {
+      case "profile-after-change":
+        gWorkerAndCallback.start();
+        Services.obs.addObserver(this, "profile-before-change", false);
+        break;
+      case "profile-before-change":
+        gWorkerAndCallback.stop();
+        break;
+      default:
+        Cu.reportError("Unknown topic: " + topic);
+    }
+  },
+
+  set callback(val) {
+    gWorkerAndCallback.callback = val;
+  },
+
+  get callback() {
+    return gWorkerAndCallback.callback;
+  },
+
+  postMessage: function(message) {
+    gWorkerAndCallback.postMessage(message);
+  },
+
+  terminate: function() {
+    gWorkerAndCallback.terminate();
+  },
+
+  QueryInterface: XPCOMUtils.generateQI([Ci.nsIObserver, Ci.nsIWorkerTest]),
+  classID: Components.ID("{3b52b935-551f-4606-ba4c-decc18b67bfd}")
+};
+
+this.NSGetFactory = XPCOMUtils.generateNSGetFactory([WorkerTest]);