Remove the old multicol implementation.

Source/core/layout/LayoutBox.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 519 matching lines @@
 
     virtual LayoutUnit computeReplacedLogicalWidth(ShouldComputePreferred  = ComputeActual) const;
     virtual LayoutUnit computeReplacedLogicalHeight() const;
 
     bool hasDefiniteLogicalWidth() const;
     static bool percentageLogicalHeightIsResolvableFromBlock(const LayoutBlock* containingBlock, bool outOfFlowPositioned);
     bool hasDefiniteLogicalHeight() const;
     LayoutUnit computePercentageLogicalHeight(const Length& height) const;
 
     // Block flows subclass availableWidth/Height to handle multi column layout (shrinking the width/height available to children when laying out.)
-    virtual LayoutUnit availableLogicalWidth() const { return contentLogicalWidth(); }
-    virtual LayoutUnit availableLogicalHeight(AvailableLogicalHeightType) const;
+    LayoutUnit availableLogicalWidth() const { return contentLogicalWidth(); }
+    LayoutUnit availableLogicalHeight(AvailableLogicalHeightType) const;
     LayoutUnit availableLogicalHeightUsing(const Length&, AvailableLogicalHeightType) const;
 
     // There are a few cases where we need to refer specifically to the available physical width and available physical height.
     // Relative positioning is one of those cases, since left/top offsets are physical.
     LayoutUnit availableWidth() const { return style()->isHorizontalWritingMode() ? availableLogicalWidth() : availableLogicalHeight(IncludeMarginBorderPadding); }
     LayoutUnit availableHeight() const { return style()->isHorizontalWritingMode() ? availableLogicalHeight(IncludeMarginBorderPadding) : availableLogicalWidth(); }
 
     virtual int verticalScrollbarWidth() const;
     int horizontalScrollbarHeight() const;
     int intrinsicScrollbarLogicalWidth() const;
@@ skipping 74 matching lines @@
         if (!UNLIKELY(hasFlippedBlocksWritingMode()))
             return position;
         return logicalHeight() - position;
     }
     LayoutPoint flipForWritingMode(const LayoutPoint& position) const WARN_UNUSED_RETURN
     {
         if (!UNLIKELY(hasFlippedBlocksWritingMode()))
             return position;
         return isHorizontalWritingMode() ? LayoutPoint(position.x(), m_frameRect.height() - position.y()) : LayoutPoint(m_frameRect.width() - position.x(), position.y());
     }
-    LayoutPoint flipForWritingModeIncludingColumns(const LayoutPoint&) const;
     LayoutSize flipForWritingMode(const LayoutSize& offset) const WARN_UNUSED_RETURN
     {
         if (!UNLIKELY(hasFlippedBlocksWritingMode()))
             return offset;
         return isHorizontalWritingMode() ? LayoutSize(offset.width(), m_frameRect.height() - offset.height()) : LayoutSize(m_frameRect.width() - offset.width(), offset.height());
     }
     void flipForWritingMode(LayoutRect& rect) const
     {
         if (!UNLIKELY(hasFlippedBlocksWritingMode()))
             return;
@@ skipping 291 matching lines @@
         if (UNLIKELY(inlineBoxWrapper() != 0))
             deleteLineBoxWrapper();
     }
 
     ensureRareData().m_inlineBoxWrapper = boxWrapper;
 }
 
 } // namespace blink
 
 #endif // LayoutBox_h