Implemented XMLSerializer in PrivateScript.

Source/core/xml/XMLSerializer.cpp

 /*
  *  Copyright (C) 2003, 2006 Apple Inc. All rights reserved.
  *  Copyright (C) 2006 Samuel Weinig (sam@webkit.org)
  *  Copyright (C) 2013 Samsung Electronics. All rights reserved.
  *
  *  This library is free software; you can redistribute it and/or
  *  modify it under the terms of the GNU Lesser General Public
  *  License as published by the Free Software Foundation; either
  *  version 2 of the License, or (at your option) any later version.
  *
  *  This library is distributed in the hope that it will be useful,
  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  *  Lesser General Public License for more details.
  *
  *  You should have received a copy of the GNU Lesser General Public
  *  License along with this library; if not, write to the Free Software
  *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
  */
 
 #include "config.h"
 #include "core/xml/XMLSerializer.h"
 
 #include "bindings/core/v8/ExceptionState.h"
+#include "bindings/core/v8/V8XMLSerializer.h"
+#include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
-#include "core/editing/MarkupAccumulator.h"
-#include "wtf/text/WTFString.h"
+#include "wtf/text/StringBuilder.h"
 
 namespace blink {
 
 String XMLSerializer::serializeToString(Node* node, ExceptionState& exceptionState)
 {
     if (!node) {
         exceptionState.throwTypeError("Invalid node value.");
         return String();
     }
 
-    MarkupAccumulator accumulator(0, DoNotResolveURLs, nullptr, ForcedXML);
-    return accumulator.serializeNodes(*node, IncludeNode);
+    String result;
+    String xmlDeclaration;
+    if (node->document().hasXMLDeclaration()) {
+        StringBuilder builder;
+        builder.appendLiteral("<?xml version=\"");

[Jens Widell, 2014/09/03 10:29:33]

IMO it seems a bit odd to serialize an XML declaration here, rather than just
passing the data in to the private script function and let it do all the
serializing.

Exposing the information (publicly) on the Document interface would have made
sense too (back when the DOM APIs were first designed, perhaps,) but at this
point adding XML stuff to it is probably not the direction we want it to move.

[tasak, 2014/09/03 11:40:46]

Firstly I tried to serialize an XML declaration in XMLSerializer.js.
However, I found that there is no way to find whether a given document has an
XML declaration or not.

I tried "if (document.xmlVersion) { ... }", but document.xmlVersion is always
"1.0". Since the API has been already shipped, I'm not sure whether we can
change the behavior or not.

And looking at Document.idl, it says "xmlVersion, xmlStandalone and xmlEncoding
are removed from DOM4". I think, we cannot create an XML declaration by using
only web-exposed API in the future.

+        builder.append(node->document().xmlVersion());
+        builder.append('\"');
+        if (!node->document().xmlEncoding().isEmpty()) {
+            builder.appendLiteral(" encoding=\"");
+            builder.append(node->document().xmlEncoding());
+            builder.append('\"');
+        }
+        if (node->document().xmlStandaloneStatus() != Document::StandaloneUnspecified)
+            builder.append(String::format(" standalone=\"%s\"", node->document().xmlStandalone() ? "yes" : "no"));
+        builder.append("?>");
+        xmlDeclaration = builder.toString();
+    }
+    V8XMLSerializer::PrivateScript::serializeToStringInternalMethod(m_document->frame(), this, node, xmlDeclaration, &result);
+    return result;
 }
 
 } // namespace blink