[CSS Grid Layout] Content Distribution support for grid.

Source/core/layout/LayoutGrid.h

 /*
  * Copyright (C) 2011 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
@@ skipping 106 matching lines @@
     LayoutUnit startOfColumnForChild(const LayoutBox& child) const;
     LayoutUnit endOfColumnForChild(const LayoutBox& child) const;
     LayoutUnit columnPositionLeft(const LayoutBox&) const;
     LayoutUnit columnPositionRight(const LayoutBox&) const;
     LayoutUnit centeredColumnPositionForChild(const LayoutBox&) const;
     LayoutUnit columnPositionForChild(const LayoutBox&) const;
     LayoutUnit startOfRowForChild(const LayoutBox& child) const;
     LayoutUnit endOfRowForChild(const LayoutBox& child) const;
     LayoutUnit centeredRowPositionForChild(const LayoutBox&) const;
     LayoutUnit rowPositionForChild(const LayoutBox&) const;
-    LayoutUnit contentPositionAndDistributionColumnOffset(LayoutUnit availableFreeSpace, ContentPosition, ContentDistributionType, OverflowAlignment, unsigned numberOfItems) const;
-    LayoutUnit contentPositionAndDistributionRowOffset(LayoutUnit availableFreeSpace, ContentPosition, ContentDistributionType, OverflowAlignment, unsigned numberOfItems) const;
-    LayoutPoint findChildLogicalPosition(const LayoutBox&, LayoutSize contentAlignmentOffset) const;
+    void computeContentPositionAndDistributionRowOffset(LayoutUnit availableFreeSpace, GridSizingData&) const;
+    void computeContentPositionAndDistributionColumnOffset(LayoutUnit availableFreeSpace, GridSizingData&) const;
+    LayoutPoint findChildLogicalPosition(const LayoutBox&, GridSizingData&) const;
     GridCoordinate cachedGridCoordinate(const LayoutBox&) const;
 
     LayoutUnit gridAreaBreadthForChild(const LayoutBox& child, GridTrackSizingDirection, const Vector<GridTrack>&) const;
 
     virtual void paintChildren(const PaintInfo&, const LayoutPoint&) override;
     bool allowedToStretchLogicalHeightForChild(const LayoutBox& child) const;
     bool needToStretchChildLogicalHeight(const LayoutBox&) const;
     LayoutUnit childIntrinsicHeight(const LayoutBox&) const;
     LayoutUnit childIntrinsicWidth(const LayoutBox&) const;
     LayoutUnit intrinsicLogicalHeightForChild(const LayoutBox&) const;
@@ skipping 31 matching lines @@
     OrderIterator m_orderIterator;
     Vector<LayoutBox*> m_gridItemsOverflowingGridArea;
     HashMap<const LayoutBox*, size_t> m_gridItemsIndexesMap;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutGrid, isLayoutGrid());
 
 } // namespace blink
 
 #endif // LayoutGrid_h