Allow overriding the serialization rules in MarkupAccumulator

Source/core/editing/MarkupAccumulator.h

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 39 matching lines @@
 
     // Non-breaking space needs to be escaped in innerHTML for compatibility reason. See http://trac.webkit.org/changeset/32879
     // However, we cannot do this in a XML document because it does not have the entity reference defined (See the bug 19215).
     EntityMaskInCDATA = 0,
     EntityMaskInPCDATA = EntityAmp | EntityLt | EntityGt,
     EntityMaskInHTMLPCDATA = EntityMaskInPCDATA | EntityNbsp,
     EntityMaskInAttributeValue = EntityAmp | EntityQuot | EntityLt | EntityGt,
     EntityMaskInHTMLAttributeValue = EntityAmp | EntityQuot | EntityNbsp,
 };
 
+enum SerializationType {
+    AsOwnerDocument,
+    ForcedXML
+};
+
 class MarkupAccumulator {
     WTF_MAKE_NONCOPYABLE(MarkupAccumulator);
 
 public:
-    MarkupAccumulator(Vector<Node*>*, EAbsoluteURLs, const Range* = 0);
+    MarkupAccumulator(Vector<Node*>*, EAbsoluteURLs, const Range* = 0, SerializationType = AsOwnerDocument);
     virtual ~MarkupAccumulator();
 
     String serializeNodes(Node& targetNode, EChildrenOnly, Vector<QualifiedName>* tagNamesToSkip = 0);
 
     static void appendComment(StringBuilder&, const String&);
 
     static void appendCharactersReplacingEntities(StringBuilder&, const String&, unsigned, unsigned, EntityMask);
 
 protected:
     void appendString(const String&);
@@ skipping 22 matching lines @@
     bool elementCannotHaveEndTag(const Node&);
     void appendEndMarkup(StringBuilder&, const Node&);
 
     Vector<Node*>* const m_nodes;
     const Range* const m_range;
 
 private:
     String resolveURLIfNeeded(const Element&, const String&) const;
     void appendQuotedURLAttributeValue(StringBuilder&, const Element&, const Attribute&);
     void serializeNodesWithNamespaces(Node& targetNode, EChildrenOnly, const Namespaces*, Vector<QualifiedName>* tagNamesToSkip);
+    bool serializeAsHTMLDocument(const Node&) const;
 
     StringBuilder m_markup;
     const EAbsoluteURLs m_resolveURLsMethod;
+    SerializationType m_serializationType;
 };
 
 }
 
 #endif