WTF::notFound looks too much like a local variable.

Source/core/rendering/RenderLayer.cpp

 /*
  * Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  *
  * Portions are Copyright (C) 1998 Netscape Communications Corporation.
  *
  * Other contributors:
  *   Robert O'Callahan <roc+@cs.cmu.edu>
  *   David Baron <dbaron@fas.harvard.edu>
  *   Christian Biesinger <cbiesinger@web.de>
  *   Randall Jesup <rjesup@wgate.com>
@@ skipping 543 matching lines @@
     ancestorStackingContext->rebuildZOrderLists(posZOrderListBeforePromote, negZOrderListBeforePromote, this, OnlyStackingContextsCanBeStackingContainers);
 
     const RenderLayer* positionedAncestor = parent();
     while (positionedAncestor && !isPositionedContainer(positionedAncestor) && !positionedAncestor->isStackingContext())
         positionedAncestor = positionedAncestor->parent();
     if (positionedAncestor && (!isPositionedContainer(positionedAncestor) || positionedAncestor->isStackingContext()))
         positionedAncestor = 0;
 
     if (!posZOrderListBeforePromote)
         posZOrderListBeforePromote = adoptPtr(new Vector<RenderLayer*>());
-    else if (posZOrderListBeforePromote->find(this) != notFound)
+    else if (posZOrderListBeforePromote->find(this) != kNotFound)
         return;
 
     // The current layer will appear in the z-order lists after promotion, so
     // for a meaningful comparison, we must insert it in the z-order lists
     // before promotion if it does not appear there already.
     if (!positionedAncestor) {
         posZOrderListBeforePromote->prepend(this);
         return;
     }
 
@@ skipping 5485 matching lines @@
     }
 }
 
 void showLayerTree(const WebCore::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif