Revert the merge. Mac build is mysteriously broken.

third_party/WebKit/WebCore/xml/XPathExpression.cpp

 /*
  * Copyright 2005 Frerich Raabe <raabe@kde.org>
  * Copyright (C) 2006 Apple Computer, Inc.
  *
  * 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.
@@ skipping 49 matching lines @@
     delete m_topExpression;
 }
 
 PassRefPtr<XPathResult> XPathExpression::evaluate(Node* contextNode, unsigned short type, XPathResult*, ExceptionCode& ec)
 {
     if (!isValidContextNode(contextNode)) {
         ec = NOT_SUPPORTED_ERR;
         return 0;
     }
 
-    Node* eventTarget = contextNode->ownerDocument() ? contextNode->ownerDocument() : contextNode;
+    EventTargetNode* eventTarget = contextNode->ownerDocument()
+        ? contextNode->ownerDocument()
+        : static_cast<EventTargetNode*>(contextNode);
 
     EvaluationContext& evaluationContext = Expression::evaluationContext();
     evaluationContext.node = contextNode;
     evaluationContext.size = 1;
     evaluationContext.position = 1;
     RefPtr<XPathResult> result = XPathResult::create(eventTarget, m_topExpression->evaluate());
     evaluationContext.node = 0; // Do not hold a reference to the context node, as this may prevent the whole document from being destroyed in time.
 
     if (type != XPathResult::ANY_TYPE) {
         ec = 0;
         result->convertTo(type, ec);
         if (ec)
             return 0;
     }
 
     return result;
 }
 
 }
 
 #endif // ENABLE(XPATH)