Use table as display item client for painting composited collapsed table cell borders.

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 268 matching lines @@
 
 #if ENABLE(ASSERT)
   bool isFirstOrLastCellInRow() const {
     return !table()->cellAfter(this) || !table()->cellBefore(this);
   }
 #endif
 
   const char* name() const override { return "LayoutTableCell"; }
 
   bool backgroundIsKnownToBeOpaqueInRect(const LayoutRect&) const override;
+  void invalidateDisplayItemClients(PaintInvalidationReason) const override;
 
-  struct CollapsedBorderValues {
-    CollapsedBorderValue startBorder;
-    CollapsedBorderValue endBorder;
-    CollapsedBorderValue beforeBorder;
-    CollapsedBorderValue afterBorder;
+  // TODO(wkorman): Consider renaming to more clearly differentiate from
+  // CollapsedBorderValue.
+  class CollapsedBorderValues : public DisplayItemClient {
+   public:
+    CollapsedBorderValues(const LayoutTable&,
+                          const CollapsedBorderValue& startBorder,
+                          const CollapsedBorderValue& endBorder,
+                          const CollapsedBorderValue& beforeBorder,
+                          const CollapsedBorderValue& afterBorder);
+
+    const CollapsedBorderValue& startBorder() const { return m_startBorder; }
+    const CollapsedBorderValue& endBorder() const { return m_endBorder; }
+    const CollapsedBorderValue& beforeBorder() const { return m_beforeBorder; }
+    const CollapsedBorderValue& afterBorder() const { return m_afterBorder; }
+
+    void setCollapsedBorderValues(const CollapsedBorderValues& other);
+
+    // DisplayItemClient methods.
+    String debugName() const;
+    LayoutRect visualRect() const;
+
+   private:
+    const LayoutTable& m_layoutTable;
+    CollapsedBorderValue m_startBorder;
+    CollapsedBorderValue m_endBorder;
+    CollapsedBorderValue m_beforeBorder;
+    CollapsedBorderValue m_afterBorder;
   };
+
+  bool usesTableAsDisplayItemClient() const;

[chrishtr, 2016/10/19 01:13:21]

usesTableAsAdditionalDisplayItemClient()

[wkorman, 2016/10/19 23:07:39]

Done.

   const CollapsedBorderValues* collapsedBorderValues() const {
     return m_collapsedBorderValues.get();
   }
 
   LayoutRect debugRect() const override;
 
   void adjustChildDebugRect(LayoutRect&) const override;
 
   // A table cell's location is relative to its containing section.
   LayoutBox* locationContainer() const override { return section(); }
@@ skipping 117 matching lines @@
   return toLayoutTableCell(firstChild());
 }
 
 inline LayoutTableCell* LayoutTableRow::lastCell() const {
   return toLayoutTableCell(lastChild());
 }
 
 }  // namespace blink
 
 #endif  // LayoutTableCell_h