diff -r 000000000000 -r 6474c204b198 dom/interfaces/xpath/nsIDOMNSXPathExpression.idl
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/interfaces/xpath/nsIDOMNSXPathExpression.idl	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,35 @@
+/* -*- Mode: IDL; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* 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 "domstubs.idl"
+
+interface nsIDOMXPathResult;
+interface XPathException;
+
+/**
+ * Interface for Mozilla specific XPathExpression functions.
+ */
+[scriptable, uuid(ce600ca8-e98a-4419-ad61-2f6d0cb0ecc8)]
+interface nsIDOMNSXPathExpression : nsISupports
+{
+  /**
+   * Evaluate the expression with the given context. Similar to
+   * nsIDOMXPathExpression::evaluate(), except that this takes the context
+   * position and size too.
+   *
+   * @param contextNode       The context node
+   * @param contextPosition   The context position
+   * @param contextSize       The context size
+   * @param type              The needed result type
+   * @param result            The result
+   */
+  nsISupports evaluateWithContext(in nsIDOMNode contextNode,
+                                  in unsigned long contextPosition,
+                                  in unsigned long contextSize,
+                                  in unsigned short type,
+                                  in nsISupports result)
+                                    raises(XPathException,
+                                           DOMException);
+};