Remove internalSubset from DocumentType

Source/core/editing/MarkupAccumulator.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2009, 2010 Google 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
@@ skipping 349 matching lines @@
         if (!n.systemId().isEmpty()) {
             result.appendLiteral(" \"");
             result.append(n.systemId());
             result.append('"');
         }
     } else if (!n.systemId().isEmpty()) {
         result.appendLiteral(" SYSTEM \"");
         result.append(n.systemId());
         result.append('"');
     }
-    if (!n.internalSubset().isEmpty()) {
-        result.appendLiteral(" [");
-        result.append(n.internalSubset());
-        result.append(']');
-    }
     result.append('>');
 }
 
 void MarkupAccumulator::appendProcessingInstruction(StringBuilder& result, const String& target, const String& data)
 {
     // FIXME: PI data is not escaped, but XMLSerializer (and possibly other callers) this should raise an exception if it includes "?>".
     result.appendLiteral("<?");
     result.append(target);
     result.append(' ');
     result.append(data);
@@ skipping 179 matching lines @@
 }
 
 bool MarkupAccumulator::serializeAsHTMLDocument(const Node& node) const
 {
     if (m_serializationType == ForcedXML)
         return false;
     return node.document().isHTMLDocument();
 }
 
 }