[css-flexbox] Cache whether our main axis size is definite

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
@@ skipping 182 matching lines @@
     // 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;
+
+    // This is set to 0/1 during layout and -1 otherwise.
+    int m_hasDefiniteHeight = -1;

[eae, 2016/07/06 23:06:09]

Use an enum for this. You might also want to pack it with
m_numberOfInFlowChildrenOnFirstLine.

 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutFlexibleBox, isFlexibleBox());
 
 } // namespace blink
 
 #endif // LayoutFlexibleBox_h