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

Source/core/dom/Position.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2009 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 786 matching lines @@
 }
 
 static int boundingBoxLogicalHeight(RenderObject *o, const IntRect &rect)
 {
     return o->style()->isHorizontalWritingMode() ? rect.height() : rect.width();
 }
 
 bool Position::hasRenderedNonAnonymousDescendantsWithHeight(RenderObject* renderer)
 {
     RenderObject* stop = renderer->nextInPreOrderAfterChildren();
-    for (RenderObject *o = renderer->firstChild(); o && o != stop; o = o->nextInPreOrder())
+    for (RenderObject *o = renderer->slowFirstChild(); o && o != stop; o = o->nextInPreOrder())
         if (o->nonPseudoNode()) {
             if ((o->isText() && boundingBoxLogicalHeight(o, toRenderText(o)->linesBoundingBox()))
                 || (o->isBox() && toRenderBox(o)->pixelSnappedLogicalHeight())
                 || (o->isRenderInline() && isEmptyInline(o) && boundingBoxLogicalHeight(o, toRenderInline(o)->linesBoundingBox())))
                 return true;
         }
     return false;
 }
 
 bool Position::nodeIsUserSelectNone(Node* node)
@@ skipping 242 matching lines @@
     return Position();
 }
 
 void Position::getInlineBoxAndOffset(EAffinity affinity, InlineBox*& inlineBox, int& caretOffset) const
 {
     getInlineBoxAndOffset(affinity, primaryDirection(), inlineBox, caretOffset);
 }
 
 static bool isNonTextLeafChild(RenderObject* object)
 {
-    if (object->firstChild())
+    if (object->slowFirstChild())
         return false;
     if (object->isText())
         return false;
     return true;
 }
 
 static InlineTextBox* searchAheadForBetterMatch(RenderObject* renderer)
 {
     RenderBlock* container = renderer->containingBlock();
     RenderObject* next = renderer;
@@ skipping 279 matching lines @@
     pos.showTreeForThis();
 }
 
 void showTree(const WebCore::Position* pos)
 {
     if (pos)
         pos->showTreeForThis();
 }
 
 #endif