Consider compositing state in row background display item client accessor.

third_party/WebKit/Source/core/layout/LayoutTableCell.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, 2007, 2009, 2013 Apple Inc.
  *               All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 319 matching lines @@
 
    private:
     const LayoutTableCell& m_layoutTableCell;
   };
 
   bool usesCompositedCellDisplayItemClients() const;
   const CollapsedBorderValues* collapsedBorderValues() const {
     return m_collapsedBorderValues.get();
   }
   const DisplayItemClient& backgroundDisplayItemClient() const {
-    return m_rowBackgroundDisplayItemClient
+    return (m_rowBackgroundDisplayItemClient &&
+            usesCompositedCellDisplayItemClients())

[Xianzhu, 2017/03/29 00:43:53]

How about keeping this as-is and changing ensureIsReadyForPaintInvalidation() to
clear m_rowBackgroundDisplayItemClient if
!usesCompositedCellDisplayItemClient()?

[Xianzhu, 2017/03/29 00:58:55]

I read your comment in the bug and now think this is good.

                ? static_cast<const DisplayItemClient&>(
                      *m_rowBackgroundDisplayItemClient)
                : *this;
   }
 
   LayoutRect debugRect() const override;
 
   void adjustChildDebugRect(LayoutRect&) const override;
 
   // A table cell's location is relative to its containing section.
@@ skipping 120 matching lines @@
   return toLayoutTableCell(firstChild());
 }
 
 inline LayoutTableCell* LayoutTableRow::lastCell() const {
   return toLayoutTableCell(lastChild());
 }
 
 }  // namespace blink
 
 #endif  // LayoutTableCell_h