Support for CSSOM CSSNamespaceRule interface

Source/core/css/CSSNamespaceRule.idl

Index: Source/core/css/CSSNamespaceRule.idl
diff --git a/Source/core/css/CSSNamespaceRule.idl b/Source/core/css/CSSNamespaceRule.idl
new file mode 100644
index 0000000000000000000000000000000000000000..d48fc9add74174225b1373f9b8470f188d9ce7d6
--- /dev/null
+++ b/Source/core/css/CSSNamespaceRule.idl
@@ -0,0 +1,12 @@
+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+
+// http://dev.w3.org/csswg/cssom-1/#the-cssnamespacerule-interface
+
+interface CSSNamespaceRule : CSSRule {
+
+    readonly attribute DOMString namespaceURI;
+    readonly attribute DOMString prefix;
+};