Cache several vectors to avoid malloc/free churn

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 54 matching lines @@
     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;
+    class GridSizingData;
     enum TrackSizingDirection { ForColumns, ForRows };
-    void computedUsedBreadthOfGridTracks(TrackSizingDirection, Vector<GridTrack>& columnTracks, Vector<GridTrack>& rowTracks);
+    void computedUsedBreadthOfGridTracks(TrackSizingDirection, GridSizingData&);
     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, const Vector<size_t>&, LayoutUnit& availableLogicalSpace);
+    void resolveContentBasedTrackSizingFunctions(TrackSizingDirection, GridSizingData&, 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(const Vector<RenderBox*>&);
     void placeAutoMajorAxisItemsOnGrid(const Vector<RenderBox*>&);
     void placeAutoMajorAxisItemOnGrid(RenderBox*);
     TrackSizingDirection autoPlacementMajorAxisDirection() const;
     TrackSizingDirection autoPlacementMinorAxisDirection() const;
 
     void layoutGridItems();
-    void populateGridPositions(const Vector<GridTrack>& columnTracks, const Vector<GridTrack>& rowTracks);
+    void populateGridPositions(const GridSizingData&);
 
     virtual bool supportsPartialLayout() const OVERRIDE { return false; }
 
     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);
+    void resolveContentBasedTrackSizingFunctionsForItems(TrackSizingDirection, GridSizingData&, RenderBox*, FilterFunction, SizingFunction, AccumulatorGetter, AccumulatorGrowFunction);
+    void distributeSpaceToTracks(Vector<GridTrack*>&, Vector<GridTrack*>* tracksForGrowthAboveMaxBreadth, AccumulatorGetter, AccumulatorGrowFunction, GridSizingData&, LayoutUnit& availableLogicalSpace);
 
     double computeNormalizedFractionBreadth(Vector<GridTrack>&, TrackSizingDirection, LayoutUnit availableLogicalSpace) const;
 
     const GridTrackSize& gridTrackSize(TrackSizingDirection, size_t) const;
     size_t explicitGridColumnCount() const;
     size_t explicitGridRowCount() const;
     size_t explicitGridSizeForSide(GridPositionSide) const;
 
     LayoutUnit logicalContentHeightForChild(RenderBox*, Vector<GridTrack>&);
     LayoutUnit minContentForChild(RenderBox*, TrackSizingDirection, Vector<GridTrack>& columnTracks);
     LayoutUnit maxContentForChild(RenderBox*, TrackSizingDirection, Vector<GridTrack>& columnTracks);
-    LayoutPoint findChildLogicalPosition(RenderBox*, const Vector<GridTrack>& columnTracks, const Vector<GridTrack>& rowTracks);
+    LayoutPoint findChildLogicalPosition(RenderBox*, const GridSizingData&);
     GridCoordinate cachedGridCoordinate(const RenderBox*) const;
 
     GridSpan resolveGridPositionsFromAutoPlacementPosition(const RenderBox*, TrackSizingDirection, size_t) const;
     PassOwnPtr<GridSpan> resolveGridPositionsFromStyle(const RenderBox*, TrackSizingDirection) const;
     size_t resolveNamedGridLinePositionFromStyle(const GridPosition&, GridPositionSide) const;
     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;
@@ skipping 40 matching lines @@
     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