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

third_party/WebKit/Source/core/layout/LayoutView.cpp

Index: third_party/WebKit/Source/core/layout/LayoutView.cpp
diff --git a/third_party/WebKit/Source/core/layout/LayoutView.cpp b/third_party/WebKit/Source/core/layout/LayoutView.cpp
index f7e4dbfcb46e5e025a097139331250fe6cbfb470..bbcfbc8701440ae29f243845c05424587e1bbcb7 100644
--- a/third_party/WebKit/Source/core/layout/LayoutView.cpp
+++ b/third_party/WebKit/Source/core/layout/LayoutView.cpp
@@ -235,10 +235,13 @@ void LayoutView::layout() {
 
   if (pageLogicalHeight() && shouldUsePrintingLayout()) {
     m_minPreferredLogicalWidth = m_maxPreferredLogicalWidth = logicalWidth();
-    if (!m_fragmentationContext)
+    if (!m_fragmentationContext) {
       m_fragmentationContext = wrapUnique(new ViewFragmentationContext(*this));
+      m_paginationStateChanged = true;
+    }
   } else if (m_fragmentationContext) {
     m_fragmentationContext.reset();
+    m_paginationStateChanged = true;
   }
 
   SubtreeLayoutScope layoutScope(*this);