Painter side preparation for subtree caching

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 62 matching lines @@
     LayoutObjectChildList* children() { return &m_children; }
 
     bool beingDestroyed() const { return m_beingDestroyed; }
 
     // These two functions are overridden for inline-block.
     LayoutUnit lineHeight(bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const final;
     int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const override;
 
     LayoutUnit minLineHeightForReplacedObject(bool isFirstLine, LayoutUnit replacedHeight) const;
 
+    const LineBoxList& lineBoxes() const { return m_lineBoxes; }
     LineBoxList* lineBoxes() { return &m_lineBoxes; }
 
     const char* name() const override;
 
 protected:
     InlineFlowBox* firstLineBox() const { return m_lineBoxes.firstLineBox(); }
     InlineFlowBox* lastLineBox() const { return m_lineBoxes.lastLineBox(); }
 
     RootInlineBox* firstRootBox() const { return static_cast<RootInlineBox*>(firstLineBox()); }
     RootInlineBox* lastRootBox() const { return static_cast<RootInlineBox*>(lastLineBox()); }
@@ skipping 328 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