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

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

Index: third_party/WebKit/Source/core/layout/LayoutState.h
diff --git a/third_party/WebKit/Source/core/layout/LayoutState.h b/third_party/WebKit/Source/core/layout/LayoutState.h
index 8bf94b0ad6cb393619b99f54f6e358397a9a6538..d8a73c6f61ce5c4b7b8d1e3db4885cfd43ca1d3e 100644
--- a/third_party/WebKit/Source/core/layout/LayoutState.h
+++ b/third_party/WebKit/Source/core/layout/LayoutState.h
@@ -104,6 +104,9 @@ class LayoutState {
     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; }
@@ -117,6 +120,7 @@ class LayoutState {
   // 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;