*** DO NOT LAND *** Measure the size and complexity of the old multicol implementation.

Source/core/rendering/RenderBox.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2006, 2007 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 528 matching lines @@
 
     virtual LayoutUnit lineHeight(bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const OVERRIDE;
     virtual int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const OVERRIDE;
 
     virtual LayoutUnit offsetLeft() const OVERRIDE;
     virtual LayoutUnit offsetTop() const OVERRIDE;
 
     LayoutPoint flipForWritingModeForChild(const RenderBox* child, const LayoutPoint&) const;
     LayoutUnit flipForWritingMode(LayoutUnit position) const; // The offset is in the block direction (y for horizontal writing modes, x for vertical writing modes).
     LayoutPoint flipForWritingMode(const LayoutPoint&) const;
-    LayoutPoint flipForWritingModeIncludingColumns(const LayoutPoint&) const;
     LayoutSize flipForWritingMode(const LayoutSize&) const;
     void flipForWritingMode(LayoutRect&) const;
     FloatPoint flipForWritingMode(const FloatPoint&) const;
     void flipForWritingMode(FloatRect&) const;
     // These represent your location relative to your container as a physical offset.
     // In layout related methods you almost always want the logical location (e.g. x() and y()).
     LayoutPoint topLeftLocation() const;
     LayoutSize topLeftLocationOffset() const;
 
     LayoutRect logicalVisualOverflowRectForPropagation(RenderStyle*) const;
@@ skipping 197 matching lines @@
         if (UNLIKELY(m_inlineBoxWrapper != 0))
             deleteLineBoxWrapper();
     }
 
     m_inlineBoxWrapper = boxWrapper;
 }
 
 } // namespace WebCore
 
 #endif // RenderBox_h