CSS Counters not properly updated on style changes

Source/core/layout/LayoutCounter.cpp

 /**
  * Copyright (C) 2004 Allan Sandfeld Jensen (kde@carewolf.com)
  * Copyright (C) 2006, 2007 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,
@@ skipping 551 matching lines @@
             // Destroying old counters that do not exist in the new counterDirective map.
             for (CounterDirectiveMap::const_iterator it = oldCounterDirectives->begin(); it !=oldMapEnd; ++it) {
                 if (!newCounterDirectives->contains(it->key))
                     LayoutCounter::destroyCounterNode(layoutObject, it->key);
             }
         } else {
             if (layoutObject.hasCounterNodeMap())
                 LayoutCounter::destroyCounterNodes(layoutObject);
         }
     } else if (newCounterDirectives) {
+        if (layoutObject.hasCounterNodeMap())
+            LayoutCounter::destroyCounterNodes(layoutObject);
         CounterDirectiveMap::const_iterator newMapEnd = newCounterDirectives->end();
         for (CounterDirectiveMap::const_iterator it = newCounterDirectives->begin(); it != newMapEnd; ++it) {
             // We must create this node here, because the added node may be a node with no display such as
             // as those created by the increment or reset directives and the re-layout that will happen will
             // not catch the change if the node had no children.
             makeCounterNode(layoutObject, it->key, false);
         }
     }
 }
 
@@ skipping 16 matching lines @@
             fprintf(stderr, "    ");
         fprintf(stderr, "%p N:%p P:%p PS:%p NS:%p C:%p\n",
             current, current->node(), current->parent(), current->previousSibling(),
             current->nextSibling(), current->hasCounterNodeMap() ?
             counterName ? blink::counterMaps().get(current)->get(identifier) : (blink::CounterNode*)1 : (blink::CounterNode*)0);
     }
     fflush(stderr);
 }
 
 #endif // NDEBUG