Implemented XMLSerializer in PrivateScript.

Source/core/xml/XMLSerializer.cpp

Index: Source/core/xml/XMLSerializer.cpp
diff --git a/Source/core/xml/XMLSerializer.cpp b/Source/core/xml/XMLSerializer.cpp
index b39aa329b9da424bc0c871a5dec4f04912158a10..8226055f810cbd7e95d676316739fc764ed19b9a 100644
--- a/Source/core/xml/XMLSerializer.cpp
+++ b/Source/core/xml/XMLSerializer.cpp
@@ -22,21 +22,34 @@
 #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();
+    String result;
+    String xmlDeclaration;
+    if (node->document().hasXMLDeclaration()) {
+        StringBuilder builder;
+        builder.appendLiteral("<?xml version=\"");
+        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();
     }
-
-    MarkupAccumulator accumulator(0, DoNotResolveURLs, nullptr, ForcedXML);
-    return accumulator.serializeNodes(*node, IncludeNode);
+    V8XMLSerializer::PrivateScript::serializeToStringInternalMethod(m_document->frame(), this, node, xmlDeclaration, &result);
+    return result;
 }
 
 } // namespace blink