diff -r 000000000000 -r 6474c204b198 xpcom/glue/nsThreadIDs.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/glue/nsThreadIDs.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,19 @@
+/* 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_threads_nsThreadIDs_h_
+#define _mozilla_threads_nsThreadIDs_h_
+
+namespace mozilla {
+namespace threads {
+
+enum ID {
+  Generic = 0,
+  Main = 1,
+};
+
+} /* namespace threads */
+} /* namespace mozilla */
+
+#endif /* _mozilla_threads_nsThreadIDs_h_ */