diff -r 000000000000 -r 6474c204b198 dom/workers/WorkerFeature.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/workers/WorkerFeature.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,78 @@
+/* -*- Mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; tab-width: 40 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_dom_workers_workerfeature_h__
+#define mozilla_dom_workers_workerfeature_h__
+
+#include "mozilla/dom/workers/Workers.h"
+
+BEGIN_WORKERS_NAMESPACE
+
+/**
+ * Use this chart to help figure out behavior during each of the closing
+ * statuses. Details below.
+ *
+ * +==============================================================+
+ * |                       Closing Statuses                       |
+ * +=============+=============+=================+================+
+ * |    status   | clear queue | abort execution |  close handler |
+ * +=============+=============+=================+================+
+ * |   Closing   |     yes     |       no        |   no timeout   |
+ * +-------------+-------------+-----------------+----------------+
+ * | Terminating |     yes     |       yes       |   no timeout   |
+ * +-------------+-------------+-----------------+----------------+
+ * |  Canceling  |     yes     |       yes       | short duration |
+ * +-------------+-------------+-----------------+----------------+
+ * |   Killing   |     yes     |       yes       |   doesn't run  |
+ * +-------------+-------------+-----------------+----------------+
+ */
+enum Status
+{
+  // Not yet scheduled.
+  Pending = 0,
+
+  // This status means that the close handler has not yet been scheduled.
+  Running,
+
+  // Inner script called close() on the worker global scope. Setting this
+  // status causes the worker to clear its queue of events but does not abort
+  // the currently running script. The close handler is also scheduled with
+  // no expiration time.
+  Closing,
+
+  // Outer script called terminate() on the worker or the worker object was
+  // garbage collected in its outer script. Setting this status causes the
+  // worker to abort immediately, clear its queue of events, and schedules the
+  // close handler with no expiration time.
+  Terminating,
+
+  // Either the user navigated away from the owning page or the owning page fell
+  // out of bfcache. Setting this status causes the worker to abort immediately
+  // and schedules the close handler with a short expiration time. Since the
+  // page has gone away the worker may not post any messages.
+  Canceling,
+
+  // The application is shutting down. Setting this status causes the worker to
+  // abort immediately and the close handler is never scheduled.
+  Killing,
+
+  // The close handler has run and the worker is effectively dead.
+  Dead
+};
+
+class WorkerFeature
+{
+public:
+  virtual ~WorkerFeature() { }
+
+  virtual bool Suspend(JSContext* aCx) { return true; }
+  virtual bool Resume(JSContext* aCx) { return true; }
+
+  virtual bool Notify(JSContext* aCx, Status aStatus) = 0;
+};
+
+END_WORKERS_NAMESPACE
+
+#endif /* mozilla_dom_workers_workerfeature_h__ */