Paint backgrounds of a table section/row in one display item

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef LayoutTableBoxComponent_h
 #define LayoutTableBoxComponent_h
 
 #include "core/CoreExport.h"
 #include "core/layout/LayoutBox.h"
+#include "core/paint/PaintResult.h"
+#include "platform/graphics/paint/CullRect.h"
 
 namespace blink {
 
 class LayoutTable;
 
 // Common super class for LayoutTableCol, LayoutTableSection and LayoutTableRow.
 class CORE_EXPORT LayoutTableBoxComponent : public LayoutBox {
  public:
   static bool doCellsHaveDirtyWidth(const LayoutObject& tablePart,
                                     const LayoutTable&,
                                     const StyleDifference&,
                                     const ComputedStyle& oldStyle);
 
+  class MutableForPainting : public LayoutObject::MutableForPainting {
+   public:
+    void updatePaintResult(PaintResult, const CullRect& paintRect);
+
+   private:
+    friend class LayoutTableBoxComponent;
+    MutableForPainting(const LayoutTableBoxComponent& box)
+        : LayoutObject::MutableForPainting(box) {}
+  };
+  MutableForPainting getMutableForPainting() const {
+    return MutableForPainting(*this);
+  }
+
  protected:
-  explicit LayoutTableBoxComponent(Element* element) : LayoutBox(element) {}
+  explicit LayoutTableBoxComponent(Element* element)
+      : LayoutBox(element), m_lastPaintResult(FullyPainted) {}
 
   const LayoutObjectChildList* children() const { return &m_children; }
   LayoutObjectChildList* children() { return &m_children; }
 
   LayoutObject* firstChild() const {
     DCHECK(children() == virtualChildren());
     return children()->firstChild();
   }
   LayoutObject* lastChild() const {
     DCHECK(children() == virtualChildren());
     return children()->lastChild();
   }
 
  private:
   // If you have a LayoutTableBoxComponent, use firstChild or lastChild instead.
   void slowFirstChild() const = delete;
   void slowLastChild() const = delete;
 
   LayoutObjectChildList* virtualChildren() override { return children(); }
   const LayoutObjectChildList* virtualChildren() const override {
     return children();
   }
 
   LayoutObjectChildList m_children;
+
+  friend class MutableForPainting;
+  PaintResult m_lastPaintResult;
+  CullRect m_lastPaintRect;
 };
 
 }  // namespace blink
 
 #endif  // LayoutTableBoxComponent_h