[css-grid] Cache definite height detection

third_party/WebKit/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 202 matching lines @@
 
     size_t gridItemSpan(const LayoutBox&, GridTrackSizingDirection);
     bool spanningItemCrossesFlexibleSizedTracks(const GridSpan&, GridTrackSizingDirection, SizingOperation) const;
 
     size_t gridColumnCount() const;
     size_t gridRowCount() const;
 
     bool isOrthogonalChild(const LayoutBox&) const;
     GridTrackSizingDirection flowAwareDirectionForChild(const LayoutBox&, GridTrackSizingDirection) const;
 
+    bool hasDefiniteLogicalHeight() const

[jfernandez, 2016/09/15 07:27:11]

This method has the same name than the one defined in LayoutBox class, but we
are not override it; we don't do it because both methods are of a different
nature, indeed. I'd rather use a different name for this getter method, to avoid
confusions and the need of specifying the class on invocation.

[svillar, 2016/09/15 08:02:22]

Agree, do not use the same name, someone could be tempted to add an override and
then we'd be ... you know :)

Also let's not add multiline implementations in the class definition, they make
it much more difficult to understand.

[Manuel Rego, 2016/09/15 08:56:04]

True, I'll change the name to cachedHasDefiniteLogicalHeight().
Done.

+    {
+        SECURITY_DCHECK(m_hasDefiniteLogicalHeight);
+        return m_hasDefiniteLogicalHeight.value();

[svillar, 2016/09/15 08:02:22]

For caching like methods I think it's preferred some other form

if (!m_hasDefiniteLogicalHeight)
   m_hasDefiniteLogicalHeight = hasDefiniteLogicalHeight();
return m_hasDefiniteLogicalHeight.value();

[svillar, 2016/09/15 08:16:00]

Beh, forget about this. We need to call it on every layout so what I was
suggesting is wrong.

+    }
+
     typedef Vector<Vector<GridCell>> GridRepresentation;
     GridRepresentation m_grid;
     bool m_gridIsDirty;
     Vector<LayoutUnit> m_rowPositions;
     Vector<LayoutUnit> m_columnPositions;
     LayoutUnit m_offsetBetweenColumns;
     LayoutUnit m_offsetBetweenRows;
     HashMap<const LayoutBox*, GridArea> m_gridItemArea;
     OrderIterator m_orderIterator;
     Vector<LayoutBox*> m_gridItemsOverflowingGridArea;
     HashMap<const LayoutBox*, size_t> m_gridItemsIndexesMap;
 
     LayoutUnit m_minContentHeight { -1 };
     LayoutUnit m_maxContentHeight { -1 };
 
     int m_smallestRowStart;
     int m_smallestColumnStart;
 
     size_t m_autoRepeatColumns { 0 };
     size_t m_autoRepeatRows { 0 };
 
     bool m_hasAnyOrthogonalChild;
 
     std::unique_ptr<OrderedTrackIndexSet> m_autoRepeatEmptyColumns { nullptr };
     std::unique_ptr<OrderedTrackIndexSet> m_autoRepeatEmptyRows { nullptr };
+
+    Optional<bool> m_hasDefiniteLogicalHeight;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutGrid, isLayoutGrid());
 
 } // namespace blink
 
 #endif // LayoutGrid_h