add 'slow' prefix to RenderObject's firstChild() / lastChild() methods

Source/core/rendering/InlineFlowBox.cpp

 /*
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 260 matching lines @@
 {
     if (!child)
         return false;
 
     if (child == ancestor)
         return true;
 
     RenderObject* curr = child;
     RenderObject* parent = curr->parent();
     while (parent && (!parent->isRenderBlock() || parent->isInline())) {
-        if (parent->lastChild() != curr)
+        if (parent->slowLastChild() != curr)
             return false;
         if (parent == ancestor)
             return true;
 
         curr = parent;
         parent = curr->parent();
     }
 
     return true;
 }
@@ skipping 1364 matching lines @@
         ASSERT(child->prevOnLine() == prev);
         prev = child;
     }
     ASSERT(prev == m_lastChild);
 #endif
 }
 
 #endif
 
 } // namespace WebCore