Avoid forcing layout on children with orthogonal flow

Source/core/rendering/RenderFlexibleBox.h

 /*
  * Copyright (C) 2011 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 46 matching lines @@
     virtual void paintChildren(PaintInfo&, const LayoutPoint&) OVERRIDE FINAL;
 
     bool isHorizontalFlow() const;
 
 protected:
     virtual void computeIntrinsicLogicalWidths(LayoutUnit& minLogicalWidth, LayoutUnit& maxLogicalWidth) const OVERRIDE;
 
     virtual bool supportsPartialLayout() const OVERRIDE { return false; }
 
     virtual void styleDidChange(StyleDifference, const RenderStyle* oldStyle) OVERRIDE;
+    virtual void removeChild(RenderObject*) OVERRIDE;
 
 private:
     enum FlexSign {
         PositiveFlexibility,
         NegativeFlexibility,
     };
 
     enum PositionedLayoutMode {
         FlipForRowReverse,
         NoFlipForRowReverse,
@@ skipping 72 matching lines @@
     void prepareChildForPositionedLayout(RenderBox* child, LayoutUnit mainAxisOffset, LayoutUnit crossAxisOffset, PositionedLayoutMode);
     size_t numberOfInFlowPositionedChildren(const OrderedFlexItemList&) const;
     void layoutAndPlaceChildren(LayoutUnit& crossAxisOffset, const OrderedFlexItemList&, const Vector<LayoutUnit>& childSizes, LayoutUnit availableFreeSpace, bool relayoutChildren, Vector<LineContext>&);
     void layoutColumnReverse(const OrderedFlexItemList&, LayoutUnit crossAxisOffset, LayoutUnit availableFreeSpace);
     void alignFlexLines(Vector<LineContext>&);
     void alignChildren(const Vector<LineContext>&);
     void applyStretchAlignmentToChild(RenderBox*, LayoutUnit lineCrossAxisExtent);
     void flipForRightToLeftColumn();
     void flipForWrapReverse(const Vector<LineContext>&, LayoutUnit crossAxisStartEdge);
 
+    // This is used to cache the preferred size for orthogonal flow children so we don't have to relayout to get it
+    HashMap<const RenderObject*, LayoutUnit> m_intrinsicSizeAlongMainAxis;
+
     mutable OrderIterator m_orderIterator;
     int m_numberOfInFlowChildrenOnFirstLine;
 };
 
 DEFINE_RENDER_OBJECT_TYPE_CASTS(RenderFlexibleBox, isFlexibleBox());
 
 } // namespace WebCore
 
 #endif // RenderFlexibleBox_h