diff -r 000000000000 -r 6474c204b198 content/xul/document/public/nsIXULOverlayProvider.idl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/content/xul/document/public/nsIXULOverlayProvider.idl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,34 @@
+/* -*- Mode: java; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/* 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/. */
+
+#include "nsISupports.idl"
+
+interface nsISimpleEnumerator;
+interface nsIURI;
+
+/**
+ * The chrome registry implements this interface to give overlays
+ * to the gecko XUL engine.
+ */
+
+[scriptable, uuid(1d5b5b94-dc47-4050-93b7-ac092e383cad)]
+interface nsIXULOverlayProvider : nsISupports
+{
+    /**
+     * Get the XUL overlays for a particular chrome URI.
+     *
+     * @param aURI  The URI being loaded
+     * @return      An enumerator of nsIURI for the overlays of this URI 
+     */
+    nsISimpleEnumerator /*nsIURI*/ getXULOverlays(in nsIURI aURI);
+
+    /**
+     * Get the style overlays for a particular chrome URI.
+     *
+     * @param aURI  The URI being loaded
+     * @return      An enumerator of nsIURI for the overlays of this URI 
+     */
+    nsISimpleEnumerator /*nsIURI*/ getStyleOverlays(in nsIURI aURI);
+};