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

Source/core/rendering/RenderListItem.cpp

 /**
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Andrew Wellington (proton@wiretapped.net)
  *
  * 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.
@@ skipping 245 matching lines @@
 {
     if (!m_hasExplicitValue) {
         m_isValueUpToDate = false;
         if (m_marker)
             m_marker->setNeedsLayoutAndPrefWidthsRecalc();
     }
 }
 
 static RenderObject* firstNonMarkerChild(RenderObject* parent)
 {
-    RenderObject* result = parent->firstChild();
+    RenderObject* result = parent->slowFirstChild();
     while (result && result->isListMarker())
         result = result->nextSibling();
     return result;
 }
 
 void RenderListItem::updateMarkerLocation()
 {
     // Sanity check the location of our marker.
     if (m_marker) {
         RenderObject* markerParent = m_marker->parent();
@@ skipping 19 matching lines @@
             LayoutStateDisabler layoutStateDisabler(*this);
             updateFirstLetter();
             m_marker->remove();
             if (markerParent)
                 markerParent->dirtyLinesFromChangedChild(m_marker);
             if (!lineBoxParent)
                 lineBoxParent = this;
             lineBoxParent->addChild(m_marker, firstNonMarkerChild(lineBoxParent));
             m_marker->updateMarginsAndContent();
             // If markerParent is an anonymous block that has lost all its children, destroy it.
-            if (markerParent && markerParent->isAnonymousBlock() && !markerParent->firstChild() && !toRenderBlock(markerParent)->continuation())
+            if (markerParent && markerParent->isAnonymousBlock() && !toRenderBlock(markerParent)->firstChild() && !toRenderBlock(markerParent)->continuation())
                 markerParent->destroy();
 
             // If the marker is inside we need to redo the preferred width calculations
             // as the size of the item now includes the size of the list marker.
             if (m_marker->isInside())
                 containingBlock()->updateLogicalWidth();
         }
     }
 }
 
@@ skipping 195 matching lines @@
             // assume that all the following ones have too.
             // This gives us the opportunity to stop here and avoid
             // marking the same nodes again.
             break;
         }
         item->updateValue();
     }
 }
 
 } // namespace WebCore