Implemented XMLSerializer in PrivateScript.

Source/core/xml/DocumentXMLSerializer.h

+// Copyright 2014 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.
+
+#ifndef DocumentXMLSerializer_h
+#define DocumentXMLSerializer_h
+
+#include "core/dom/Document.h"
+
+namespace blink {
+
+class DocumentXMLSerializer {
+public:
+    static bool hasXMLDeclaration(Document& document)
+    {
+        return document.hasXMLDeclaration();
+    }
+
+    static bool isXMLStandaloneSpecified(Document& document)
+    {
+        return document.xmlStandaloneStatus() != Document::StandaloneUnspecified;
+    }
+};
+
+}
+#endif