diff -r 000000000000 -r 6474c204b198 dom/xslt/xpath/txXPathOptimizer.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dom/xslt/xpath/txXPathOptimizer.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,31 @@
+/* -*- Mode: C++; tab-width: 4; 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/. */
+
+#ifndef txXPathOptimizer_h__
+#define txXPathOptimizer_h__
+
+#include "txCore.h"
+
+class Expr;
+
+class txXPathOptimizer
+{
+public:
+    /**
+     * Optimize the given expression.
+     * @param aInExpr       Expression to optimize.
+     * @param aOutExpr      Resulting expression, null if optimization didn't
+     *                      result in a new expression.
+     */
+    nsresult optimize(Expr* aInExpr, Expr** aOutExpr);
+
+private:
+    // Helper methods for optimizing specific classes
+    nsresult optimizeStep(Expr* aInExpr, Expr** aOutExpr);
+    nsresult optimizePath(Expr* aInExpr, Expr** aOutExpr);
+    nsresult optimizeUnion(Expr* aInExpr, Expr** aOutExpr);
+};
+
+#endif