Deduct pagination struts when calculating initial column height.

third_party/WebKit/Source/core/layout/MultiColumnFragmentainerGroup.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MultiColumnFragmentainerGroup_h
 #define MultiColumnFragmentainerGroup_h
 
 #include "core/layout/LayoutMultiColumnFlowThread.h"
 #include "wtf/Allocator.h"
 
@@ skipping 54 matching lines @@
     bool recalculateColumnHeight(BalancedColumnHeightCalculation calculationMode);
 
     LayoutSize flowThreadTranslationAtOffset(LayoutUnit offsetInFlowThread) const;
     LayoutUnit columnLogicalTopForOffset(LayoutUnit offsetInFlowThread) const;
     LayoutPoint visualPointToFlowThreadPoint(const LayoutPoint& visualPoint) const;
     LayoutRect fragmentsBoundingBox(const LayoutRect& boundingBoxInFlowThread) const;
 
     void collectLayerFragments(PaintLayerFragments&, const LayoutRect& layerBoundingBox, const LayoutRect& dirtyRect) const;
     LayoutRect calculateOverflow() const;
 
+    enum ColumnIndexCalculationMode {
+        ClampToExistingColumns, // Stay within the range of already existing columns.
+        AssumeNewColumns // Allow column indices outside the range of already existing columns.
+    };
+    unsigned columnIndexAtOffset(LayoutUnit offsetInFlowThread, ColumnIndexCalculationMode = ClampToExistingColumns) const;
+
     // The "CSS actual" value of column-count. This includes overflowing columns, if any.
     unsigned actualColumnCount() const;
 
 private:
     LayoutUnit heightAdjustedForRowOffset(LayoutUnit height) const;
     LayoutUnit calculateMaxColumnHeight() const;
     void setAndConstrainColumnHeight(LayoutUnit);
 
     LayoutUnit calculateColumnHeight(BalancedColumnHeightCalculation) const;
 
     LayoutRect columnRectAt(unsigned columnIndex) const;
     LayoutUnit logicalTopInFlowThreadAt(unsigned columnIndex) const { return m_logicalTopInFlowThread + columnIndex * m_columnHeight; }
     LayoutRect flowThreadPortionRectAt(unsigned columnIndex) const;
     LayoutRect flowThreadPortionOverflowRectAt(unsigned columnIndex) const;
 
-    enum ColumnIndexCalculationMode {
-        ClampToExistingColumns, // Stay within the range of already existing columns.
-        AssumeNewColumns // Allow column indices outside the range of already existing columns.
-    };
-    unsigned columnIndexAtOffset(LayoutUnit offsetInFlowThread, ColumnIndexCalculationMode = ClampToExistingColumns) const;
-
     // Return the column that the specified visual point belongs to. Only the coordinate on the
     // column progression axis is relevant. Every point belongs to a column, even if said point is
     // not inside any of the columns.
     unsigned columnIndexAtVisualPoint(const LayoutPoint& visualPoint) const;
 
     // Get the first and the last column intersecting the specified block range.
     // Note that |logicalBottomInFlowThread| is an exclusive endpoint.
     void columnIntervalForBlockRangeInFlowThread(LayoutUnit logicalTopInFlowThread, LayoutUnit logicalBottomInFlowThread, unsigned& firstColumn, unsigned& lastColumn) const;
 
     // Get the first and the last column intersecting the specified visual rectangle.
@@ skipping 49 matching lines @@
 
 private:
     LayoutMultiColumnSet& m_columnSet;
 
     Vector<MultiColumnFragmentainerGroup, 1> m_groups;
 };
 
 } // namespace blink
 
 #endif // MultiColumnFragmentainerGroup_h