[oilpan] The Node hierarchy should have correct accept method chains

Source/core/html/HTMLViewSourceDocument.cpp

 /*
  * Copyright (C) 2006, 2008, 2009, 2010 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 299 matching lines @@
     else
         classValue = "webkit-html-attribute-value webkit-html-resource-link";
     anchor->setAttribute(classAttr, classValue);
     anchor->setAttribute(targetAttr, "_blank");
     anchor->setAttribute(hrefAttr, url);
     m_current->parserAppendChild(anchor);
     anchor->attach();
     return anchor.passRefPtr();
 }
 
+void HTMLViewSourceDocument::acceptHeapVisitor(Visitor* visitor) const
+{
+    HTMLDocument::acceptHeapVisitor(visitor);
 }
+
+}