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

Source/core/plugins/PluginOcclusionSupport.cpp

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 82 matching lines @@
                 }
                 return true;
             }
 
             // Inspect the document order. Later order means higher stacking.
             const RenderObject* parent = ro1->parent();
             if (!parent)
                 return false;
             ASSERT(parent == ro2->parent());
 
-            for (const RenderObject* ro = parent->firstChild(); ro; ro = ro->nextSibling()) {
+            for (const RenderObject* ro = parent->slowFirstChild(); ro; ro = ro->nextSibling()) {
                 if (ro == ro1)
                     return false;
                 if (ro == ro2)
                     return true;
             }
             ASSERT(false); // We should have seen ro1 and ro2 by now.
             return false;
         }
     }
     return true;
@@ skipping 11 matching lines @@
     IntSize size(renderer->width(), renderer->height());
     occlusions.append(IntRect(point, size));
 }
 
 static void addTreeToOcclusions(const RenderObject* renderer, const IntRect& frameRect, Vector<IntRect>& occlusions)
 {
     if (!renderer)
         return;
     if (renderer->isBox() && intersectsRect(renderer, frameRect))
         addToOcclusions(toRenderBox(renderer), occlusions);
-    for (RenderObject* child = renderer->firstChild(); child; child = child->nextSibling())
+    for (RenderObject* child = renderer->slowFirstChild(); child; child = child->nextSibling())
         addTreeToOcclusions(child, frameRect, occlusions);
 }
 
 static const Element* topLayerAncestor(const Element* element)
 {
     while (element && !element->isInTopLayer())
         element = element->parentOrShadowHostElement();
     return element;
 }
 
@@ skipping 47 matching lines @@
     // as being in the top layer.
     const Element* ancestor = topLayerAncestor(element);
     Document* document = parentFrameView->frame().document();
     const WillBeHeapVector<RefPtrWillBeMember<Element> >& elements = document->topLayerElements();
     size_t start = ancestor ? elements.find(ancestor) + 1 : 0;
     for (size_t i = start; i < elements.size(); ++i)
         addTreeToOcclusions(elements[i]->renderer(), frameRect, occlusions);
 }
 
 } // namespace WebCore