Notify the counter code about layout object removals BEFORE removing.

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 450 matching lines @@
     // directives must occur, in which case, LayoutCounter::destroyCounterNodes()
     // must be called.
     // The destruction of the LayoutObject (possibly caused by the removal of its
     // associated DOM node) is the other case that leads to the permanent
     // destruction of all counters attached to a LayoutObject. In this case
     // LayoutCounter::destroyCounterNodes() must be and is now called, too.
     // LayoutCounter::destroyCounterNodes() handles destruction of the counter
     // map associated with a layoutObject, so there is no risk in leaking the map.
 }
 
-void LayoutCounter::layoutObjectRemovedFromTree(LayoutObject* layoutObject)
+void LayoutCounter::layoutObjectSubtreeWillBeDetached(LayoutObject* layoutObject)
 {
     ASSERT(layoutObject->view());
     if (!layoutObject->view()->hasLayoutCounters())
         return;
     LayoutObject* currentLayoutObject = layoutObject->lastLeafChild();
     if (!currentLayoutObject)
         currentLayoutObject = layoutObject;
     while (true) {
         destroyCounterNodes(*currentLayoutObject);
         if (currentLayoutObject == layoutObject)
@@ skipping 116 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