[css-flexbox] More correctly implement percentage sizing

third_party/WebKit/Source/core/layout/LayoutFlexibleBox.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
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     void alignChildren(const Vector<LineContext>&);
     void applyStretchAlignmentToChild(LayoutBox& child, LayoutUnit lineCrossAxisExtent);
     void flipForRightToLeftColumn();
     void flipForWrapReverse(const Vector<LineContext>&, LayoutUnit crossAxisStartEdge);
 
     float countIntrinsicSizeForAlgorithmChange(LayoutUnit maxPreferredWidth, LayoutBox* child, float previousMaxContentFlexFraction) const;
 
     // This is used to cache the preferred size for orthogonal flow children so we don't have to relayout to get it
     HashMap<const LayoutObject*, LayoutUnit> m_intrinsicSizeAlongMainAxis;
 
+    // This set is used to keep track of which children we laid out in this current layout iteration.
+    // We need it because the ones in this set may need an additional layout pass for correct stretch alignment
+    // handling, as the first layout likely did not use the correct value for percentage sizing of children.
+    HashSet<const LayoutObject*> m_relaidOutChildren;
+
     mutable OrderIterator m_orderIterator;
     int m_numberOfInFlowChildrenOnFirstLine;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutFlexibleBox, isFlexibleBox());
 
 } // namespace blink
 
 #endif // LayoutFlexibleBox_h