Subtree caching implementation in blink-core

Source/core/layout/LayoutBlock.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2007 David Smith (catfish.man@gmail.com)
  * Copyright (C) 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 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
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
@@ skipping 280 matching lines @@
 
     void addOutlineRects(Vector<LayoutRect>&, const LayoutPoint& additionalOffset) const override;
 
     void computeSelfHitTestRects(Vector<LayoutRect>&, const LayoutPoint& layerOffset) const override;
 
     void updateBlockChildDirtyBitsBeforeLayout(bool relayoutChildren, LayoutBox&);
 
     bool isInlineBlockOrInlineTable() const final { return isInline() && isReplaced(); }
 
     void invalidatePaintOfSubtreesIfNeeded(PaintInvalidationState& childPaintInvalidationState) override;
-    void invalidateDisplayItemClients(const LayoutBoxModelObject& paintInvalidationContainer) const override;
+    void invalidateDisplayItemClients(const LayoutBoxModelObject& paintInvalidationContainer) override;
+    bool clearRepaintFlagsOfSubtrees() override;
 
 private:
     LayoutObjectChildList* virtualChildren() final { return children(); }
     const LayoutObjectChildList* virtualChildren() const final { return children(); }
 
     bool isLayoutBlock() const final { return true; }
 
     void makeChildrenNonInline(LayoutObject* insertionPoint = nullptr);
 
     // Promote all children and make them siblings that come right after this block.
@@ skipping 116 matching lines @@
     // FIXME: This is temporary as we move code that accesses block flow
     // member variables out of LayoutBlock and into LayoutBlockFlow.
     friend class LayoutBlockFlow;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutBlock, isLayoutBlock());
 
 } // namespace blink
 
 #endif // LayoutBlock_h