Handle nested theads correctly when paginated

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

 /*
  * Copyright (C) 1997 Martin Jones (mjones@kde.org)
  *           (C) 1997 Torben Weis (weis@kde.org)
  *           (C) 1998 Waldo Bastian (bastian@kde.org)
  *           (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2004, 2005, 2006, 2009, 2013 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
@@ skipping 281 matching lines @@
     const char* name() const override { return "LayoutTableSection"; }
 
     // Whether a section has opaque background depends on many factors, e.g. border spacing,
     // border collapsing, missing cells, etc.
     // For simplicity, just conservatively assume all table sections are not opaque.
     bool foregroundIsKnownToBeOpaqueInRect(const LayoutRect&, unsigned) const override { return false; }
     bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const override { return false; }
 
     int paginationStrutForRow(LayoutTableRow*, LayoutUnit logicalOffset) const;
 
+    void setOffsetForRepeatingHeader(LayoutUnit offset) { m_offsetForRepeatingHeader = offset; }
+    LayoutUnit offsetForRepeatingHeader() const { return m_offsetForRepeatingHeader; }
+
 protected:
     void styleDidChange(StyleDifference, const ComputedStyle* oldStyle) override;
     bool nodeAtPoint(HitTestResult&, const HitTestLocation& locationInContainer, const LayoutPoint& accumulatedOffset, HitTestAction) override;
 
 private:
     bool isOfType(LayoutObjectType type) const override { return type == LayoutObjectTableSection || LayoutBox::isOfType(type); }
 
     void willBeRemovedFromTree() override;
 
     void layout() override;
@@ skipping 71 matching lines @@
     // and m_forceSlowPaintPathWithOverflowingCell will be set to save memory.
     HashSet<LayoutTableCell*> m_overflowingCells;
     bool m_forceSlowPaintPathWithOverflowingCell;
 
     // This boolean tracks if we have cells overlapping due to rowspan / colspan
     // (see class comment above about when it could appear).
     //
     // The use is to disable a painting optimization where we just paint the
     // invalidated cells.
     bool m_hasMultipleCellLevels;
+
+    LayoutUnit m_offsetForRepeatingHeader;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutTableSection, isTableSection());
 
 } // namespace blink
 
 #endif // LayoutTableSection_h