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

Source/core/rendering/LayoutState.h

 /*
  * Copyright (C) 2007 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef LayoutState_h
 #define LayoutState_h
 
-#include "core/rendering/ColumnInfo.h"
 #include "platform/geometry/LayoutRect.h"
 #include "wtf/HashMap.h"
 #include "wtf/Noncopyable.h"
 
 namespace WebCore {
 
 class RenderBlockFlow;
 class RenderBox;
 class RenderObject;
 class RenderFlowThread;
 class ShapeInsideInfo;
 
 class LayoutState {
     WTF_MAKE_NONCOPYABLE(LayoutState);
 public:
     LayoutState()
         : m_clipped(false)
         , m_isPaginated(false)
         , m_pageLogicalHeightChanged(false)
 #if !ASSERT_DISABLED
         , m_layoutDeltaXSaturated(false)
         , m_layoutDeltaYSaturated(false)
 #endif
-        , m_columnInfo(0)
         , m_lineGrid(0)
         , m_next(0)
         , m_shapeInsideInfo(0)
         , m_pageLogicalHeight(0)
 #ifndef NDEBUG
         , m_renderer(0)
 #endif
     {
     }
 
-    LayoutState(LayoutState*, RenderBox*, const LayoutSize& offset, LayoutUnit pageHeight, bool pageHeightChanged, ColumnInfo*);
+    LayoutState(LayoutState*, RenderBox*, const LayoutSize& offset, LayoutUnit pageHeight, bool pageHeightChanged);
     LayoutState(RenderObject*);
 
     // LayoutState is allocated out of the rendering partition.
     void* operator new(size_t);
     void operator delete(void*);
 
-    void clearPaginationInformation();
-    bool isPaginatingColumns() const { return m_columnInfo && m_columnInfo->paginationUnit() == ColumnInfo::Column; }
     bool isPaginated() const { return m_isPaginated; }
 
     // The page logical offset is the object's offset from the top of the page in the page progression
     // direction (so an x-offset in vertical text and a y-offset for horizontal text).
     LayoutUnit pageLogicalOffset(RenderBox*, LayoutUnit childLogicalOffset) const;
 
-    void addForcedColumnBreak(RenderBox*, LayoutUnit childLogicalOffset);
-
     LayoutUnit pageLogicalHeight() const { return m_pageLogicalHeight; }
     bool pageLogicalHeightChanged() const { return m_pageLogicalHeightChanged; }
 
     RenderBlockFlow* lineGrid() const { return m_lineGrid; }
     LayoutSize lineGridOffset() const { return m_lineGridOffset; }
     LayoutSize lineGridPaginationOrigin() const { return m_lineGridPaginationOrigin; }
 
     LayoutSize layoutOffset() const { return m_layoutOffset; }
 
     bool needsBlockDirectionLocationSetBeforeLayout() const { return m_lineGrid || (m_isPaginated && m_pageLogicalHeight); }
 
     ShapeInsideInfo* shapeInsideInfo() const { return m_shapeInsideInfo; }
 
 #ifndef NDEBUG
     RenderObject* renderer() const { return m_renderer; }
 #endif
 private:
     void propagateLineGridInfo(RenderBox*);
     void establishLineGrid(RenderBlockFlow*);
 
-    void computeLineGridPaginationOrigin(RenderBox*);
-
 public:
-    // Do not add anything apart from bitfields until after m_columnInfo. See https://bugs.webkit.org/show_bug.cgi?id=100173
+    // Do not add anything apart from bitfields until after m_lineGrid. See https://bugs.webkit.org/show_bug.cgi?id=100173
     bool m_clipped:1;
     bool m_isPaginated:1;
     // If our page height has changed, this will force all blocks to relayout.
     bool m_pageLogicalHeightChanged:1;
 #if !ASSERT_DISABLED
     bool m_layoutDeltaXSaturated:1;
     bool m_layoutDeltaYSaturated:1;
 #endif
-    // If the enclosing pagination model is a column model, then this will store column information for easy retrieval/manipulation.
-    ColumnInfo* m_columnInfo;
     // The current line grid that we're snapping to and the offset of the start of the grid.
     RenderBlockFlow* m_lineGrid;
     LayoutState* m_next;
     ShapeInsideInfo* m_shapeInsideInfo;
 
     // FIXME: Distinguish between the layout clip rect and the paint clip rect which may be larger,
     // e.g., because of composited scrolling.
     LayoutRect m_clipRect;
 
     // x/y offset from container. Includes relative positioning and scroll offsets.
@@ skipping 13 matching lines @@
     LayoutSize m_lineGridPaginationOrigin;
 
 #ifndef NDEBUG
     RenderObject* m_renderer;
 #endif
 };
 
 } // namespace WebCore
 
 #endif // LayoutState_h