[CSS Grid Layout] Store m_grid across layout

Source/core/rendering/RenderGrid.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 36 matching lines @@
     RenderGrid(Element*);
     virtual ~RenderGrid();
 
     virtual const char* renderName() const OVERRIDE;
 
     virtual void layoutBlock(bool relayoutChildren, LayoutUnit pageLogicalHeight = 0) OVERRIDE;
 
     virtual bool avoidsFloats() const OVERRIDE { return true; }
     virtual bool canCollapseAnonymousBlockChild() const OVERRIDE { return false; }
 
+    void dirtyGrid();
+
 private:
     virtual bool isRenderGrid() const OVERRIDE { return true; }
     virtual void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const OVERRIDE;
     virtual void computePreferredLogicalWidths() OVERRIDE;
 
+    virtual void addChild(RenderObject* newChild, RenderObject* beforeChild = 0) OVERRIDE;
+    virtual void removeChild(RenderObject*) OVERRIDE;
+
+    virtual void styleDidChange(StyleDifference, const RenderStyle*) OVERRIDE;
+
+    bool explicitGridDidResize(const RenderStyle*) const;
+    bool namedGridLinesDefinitionDidChange(const RenderStyle*) const;
+
     LayoutUnit computePreferredTrackWidth(const GridLength&, size_t) const;
 
     class GridIterator;
     enum TrackSizingDirection { ForColumns, ForRows };
     void computedUsedBreadthOfGridTracks(TrackSizingDirection, Vector<GridTrack>& columnTracks, Vector<GridTrack>& rowTracks);
     LayoutUnit computeUsedBreadthOfMinLength(TrackSizingDirection, const GridLength&) const;
     LayoutUnit computeUsedBreadthOfMaxLength(TrackSizingDirection, const GridLength&, LayoutUnit usedBreadth) const;
     LayoutUnit computeUsedBreadthOfSpecifiedLength(TrackSizingDirection, const Length&) const;
     void resolveContentBasedTrackSizingFunctions(TrackSizingDirection, Vector<GridTrack>& columnTracks, Vector<GridTrack>& rowTracks, LayoutUnit& availableLogicalSpace);
 
     void growGrid(TrackSizingDirection);
     void insertItemIntoGrid(RenderBox*, size_t rowTrack, size_t columnTrack);
     void insertItemIntoGrid(RenderBox*, const GridCoordinate&);
     void placeItemsOnGrid();
     void populateExplicitGridAndOrderIterator();
     void placeSpecifiedMajorAxisItemsOnGrid(Vector<RenderBox*>);
     void placeAutoMajorAxisItemsOnGrid(Vector<RenderBox*>);
     void placeAutoMajorAxisItemOnGrid(RenderBox*);
     TrackSizingDirection autoPlacementMajorAxisDirection() const;
     TrackSizingDirection autoPlacementMinorAxisDirection() const;
 
     void layoutGridItems();
-    void clearGrid();
 
     typedef LayoutUnit (RenderGrid::* SizingFunction)(RenderBox*, TrackSizingDirection, Vector<GridTrack>&);
     typedef LayoutUnit (GridTrack::* AccumulatorGetter)() const;
     typedef void (GridTrack::* AccumulatorGrowFunction)(LayoutUnit);
     typedef bool (GridTrackSize::* FilterFunction)() const;
     void resolveContentBasedTrackSizingFunctionsForItems(TrackSizingDirection, Vector<GridTrack>& columnTracks, Vector<GridTrack>& rowTracks, RenderBox*, FilterFunction, SizingFunction, AccumulatorGetter, AccumulatorGrowFunction);
     void distributeSpaceToTracks(Vector<GridTrack*>&, Vector<GridTrack*>* tracksForGrowthAboveMaxBreadth, AccumulatorGetter, AccumulatorGrowFunction, LayoutUnit& availableLogicalSpace);
 
     double computeNormalizedFractionBreadth(Vector<GridTrack>&, TrackSizingDirection, LayoutUnit availableLogicalSpace) const;
 
@@ skipping 14 matching lines @@
     size_t resolveGridPositionFromStyle(const GridPosition&, GridPositionSide) const;
     PassOwnPtr<GridSpan> resolveGridPositionAgainstOppositePosition(size_t resolvedOppositePosition, const GridPosition&, GridPositionSide) const;
     PassOwnPtr<GridSpan> resolveNamedGridLinePositionAgainstOppositePosition(size_t resolvedOppositePosition, const GridPosition&, GridPositionSide) const;
     PassOwnPtr<GridSpan> resolveBeforeStartNamedGridLinePositionAgainstOppositePosition(size_t resolvedOppositePosition, const GridPosition&, const Vector<size_t>&) const;
     PassOwnPtr<GridSpan> resolveAfterEndNamedGridLinePositionAgainstOppositePosition(size_t resolvedOppositePosition, const GridPosition&, const Vector<size_t>&) const;
 
     LayoutUnit gridAreaBreadthForChild(const RenderBox* child, TrackSizingDirection, const Vector<GridTrack>&) const;
 
     virtual void paintChildren(PaintInfo&, const LayoutPoint&) OVERRIDE FINAL;
 
+    bool gridIsDirty() const { return m_gridIsDirty; }
+
 #ifndef NDEBUG
     bool tracksAreWiderThanMinTrackBreadth(TrackSizingDirection, const Vector<GridTrack>&);
-    bool gridWasPopulated() const { return !m_grid.isEmpty() && !m_grid[0].isEmpty(); }
 #endif
 
     size_t gridColumnCount() const
     {
-        ASSERT(gridWasPopulated());
+        ASSERT(!gridIsDirty());
         return m_grid[0].size();
     }
     size_t gridRowCount() const
     {
-        ASSERT(gridWasPopulated());
+        ASSERT(!gridIsDirty());
         return m_grid.size();
     }
 
     Vector<Vector<Vector<RenderBox*, 1> > > m_grid;
+    bool m_gridIsDirty;
     HashMap<const RenderBox*, GridCoordinate> m_gridItemCoordinate;
     OrderIterator m_orderIterator;
 };
 
+inline RenderGrid* toRenderGrid(RenderObject* object)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderGrid());
+    return static_cast<RenderGrid*>(object);
+}
+
+inline const RenderGrid* toRenderGrid(const RenderObject* object)
+{
+    ASSERT_WITH_SECURITY_IMPLICATION(!object || object->isRenderGrid());
+    return static_cast<const RenderGrid*>(object);
+}
+
+// Catch unneeded cast.
+void toRenderGrid(const RenderGrid*);
+
 } // namespace WebCore
 
 #endif // RenderGrid_h