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

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

 /*
  * Copyright (C) 2007 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 86 matching lines @@
   };
 
   const LayoutSize& layoutOffset() const { return m_layoutOffset; }
   const LayoutSize& pageOffset() const { return m_pageOffset; }
   LayoutUnit pageLogicalHeight() const { return m_pageLogicalHeight; }
   bool pageLogicalHeightChanged() const { return m_pageLogicalHeightChanged; }
   bool containingBlockLogicalWidthChanged() const {
     return m_containingBlockLogicalWidthChanged;
   }
 
+  bool paginationStateChanged() const { return m_paginationStateChanged; }
+  void setPaginationStateChanged() { m_paginationStateChanged = true; }
+
   LayoutState* next() const { return m_next; }
 
   LayoutFlowThread* flowThread() const { return m_flowThread; }
 
   LayoutObject& layoutObject() const { return m_layoutObject; }
 
  private:
   // Do not add anything apart from bitfields until after m_flowThread. See
   // https://bugs.webkit.org/show_bug.cgi?id=100173
   bool m_isPaginated : 1;
   // If our page height has changed, this will force all blocks to relayout.
   bool m_pageLogicalHeightChanged : 1;
   bool m_containingBlockLogicalWidthChanged : 1;
+  bool m_paginationStateChanged : 1;
 
   LayoutFlowThread* m_flowThread;
 
   LayoutState* m_next;
 
   // x/y offset from container. Does not include relative positioning or scroll
   // offsets.
   LayoutSize m_layoutOffset;
 
   // The current page height for the pagination model that encloses us.
   LayoutUnit m_pageLogicalHeight;
 
   // The height we need to make available for repeating table headers in
   // paginated layout.
   LayoutUnit m_heightOffsetForTableHeaders;
 
   // The offset of the start of the first page in the nearest enclosing
   // pagination model.
   LayoutSize m_pageOffset;
 
   LayoutObject& m_layoutObject;
 };
 
 }  // namespace blink
 
 #endif  // LayoutState_h