Need a deep layout pass when becoming (un)fragmented.

third_party/WebKit/Source/core/layout/LayoutBlock.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 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
@@ skipping 527 matching lines @@
   unsigned m_hasMarkupTruncation : 1;
   unsigned m_widthAvailableToChildrenChanged : 1;
   unsigned m_heightAvailableToChildrenChanged : 1;
   unsigned m_isSelfCollapsing : 1;  // True if margin-before and margin-after
                                     // are adjoining.
   unsigned m_descendantsWithFloatsMarkedForLayout : 1;
 
   unsigned m_hasPositionedObjects : 1;
   unsigned m_hasPercentHeightDescendants : 1;
 
+  // When an object ceases to establish a fragmentation context (e.g. the
+  // LayoutView when we're no longer printing), we need a deep layout
+  // afterwards, to clear all pagination struts. Likewise, when an object
+  // becomes fragmented, we need to re-lay out the entire subtree. There might
+  // be forced breaks somewhere in there that we suddenly have to pay attention
+  // to, for all we know.
+  unsigned m_paginationStateChanged : 1;
+
   // FIXME: This is temporary as we move code that accesses block flow
   // member variables out of LayoutBlock and into LayoutBlockFlow.
   friend class LayoutBlockFlow;
 
   // This is necessary for now for interoperability between the old and new
   // layout code. Primarily for calling layoutPositionedObjects at the moment.
   friend class NGBox;
 
  public:
   // TODO(lunalu): Temporary in order to ensure compatibility with existing
   // layout test results.
   virtual void adjustChildDebugRect(LayoutRect&) const {}
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutBlock, isLayoutBlock());
 
 }  // namespace blink
 
 #endif  // LayoutBlock_h