Need to reset enclosingPaginationLayer when a RenderLayer is removed from the tree.

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 517 matching lines @@
     for (RenderLayer* curr = parent(); curr; curr = curr->parent()) {
         if (curr->renderer()->hasColumns()) {
             m_isPaginated = checkContainingBlockChainForPagination(renderer(), curr->renderBox());
             return;
         }
         if (curr->stackingNode() == ancestorStackingContextNode)
             return;
     }
 }
 
+void RenderLayer::clearPaginationRecursive()
+{
+    m_enclosingPaginationLayer = 0;
+    for (RenderLayer* child = firstChild(); child; child = child->nextSibling())
+        child->clearPaginationRecursive();
+}
+
 LayoutPoint RenderLayer::positionFromPaintInvalidationBacking(const RenderObject* renderObject, const RenderLayerModelObject* paintInvalidationContainer, const PaintInvalidationState* paintInvalidationState)
 {
     FloatPoint point = renderObject->localToContainerPoint(FloatPoint(), paintInvalidationContainer, 0, 0, paintInvalidationState);
 
     // FIXME: Eventually we are going to unify coordinates in GraphicsLayer space.
     if (paintInvalidationContainer && paintInvalidationContainer->layer()->groupedMapping())
         mapPointToPaintBackingCoordinates(paintInvalidationContainer, point);
 
     return LayoutPoint(point);
 }
@@ skipping 684 matching lines @@
     oldChild->setNextSibling(0);
     oldChild->m_parent = 0;
 
     dirtyAncestorChainHasSelfPaintingLayerDescendantStatus();
 
     oldChild->updateDescendantDependentFlags();
 
     if (oldChild->m_hasVisibleContent || oldChild->m_hasVisibleDescendant)
         dirtyAncestorChainVisibleDescendantStatus();
 
+    if (oldChild->enclosingPaginationLayer())
+        oldChild->clearPaginationRecursive();
+
     return oldChild;
 }
 
 void RenderLayer::removeOnlyThisLayer()
 {
     if (!m_parent)
         return;
 
     m_clipper.clearClipRectsIncludingDescendants();
 
@@ skipping 1587 matching lines @@
     }
 }
 
 void showLayerTree(const blink::RenderObject* renderer)
 {
     if (!renderer)
         return;
     showLayerTree(renderer->enclosingLayer());
 }
 #endif