diff -r 000000000000 -r 6474c204b198 dom/webidl/XMLSerializer.webidl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/webidl/XMLSerializer.webidl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,20 @@
+/* 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/.
+ *
+ * The origin of this IDL file is
+ * http://domparsing.spec.whatwg.org/#the-xmlserializer-interface
+ */
+
+interface OutputStream;
+
+[Constructor]
+interface XMLSerializer {
+  [Throws]
+  DOMString serializeToString(Node root);
+
+  // Mozilla-specific stuff
+  [Throws, ChromeOnly]
+  void serializeToStream(Node root, OutputStream stream, DOMString? charset);
+};
+