Blink doesn't honor percent heights on children of "align-self:stretch" flex items in a fixed-height

Source/core/rendering/RenderBox.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2003, 2006, 2007 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 529 matching lines @@
     virtual int inlineBlockBaseline(LineDirectionMode) const { return -1; } // Returns -1 if we should skip this box when computing the baseline of an inline-block.
 
     bool shrinkToAvoidFloats() const;
     virtual bool avoidsFloats() const;
 
     virtual void markForPaginationRelayoutIfNeeded(SubtreeLayoutScope&);
 
     bool isWritingModeRoot() const { return !parent() || parent()->style()->writingMode() != style()->writingMode(); }
 
     bool isDeprecatedFlexItem() const { return !isInline() && !isFloatingOrOutOfFlowPositioned() && parent() && parent()->isDeprecatedFlexibleBox(); }
+    bool isFlexItem() const { return !isInline() && !isFloatingOrOutOfFlowPositioned() && parent() && parent()->isFlexibleBox(); }
     bool isFlexItemIncludingDeprecated() const { return !isInline() && !isFloatingOrOutOfFlowPositioned() && parent() && parent()->isFlexibleBoxIncludingDeprecated(); }
 
     virtual LayoutUnit lineHeight(bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const OVERRIDE;
     virtual int baselinePosition(FontBaseline, bool firstLine, LineDirectionMode, LinePositionMode = PositionOnContainingLine) const OVERRIDE;
 
     virtual LayoutUnit offsetLeft() const OVERRIDE;
     virtual LayoutUnit offsetTop() const OVERRIDE;
 
     LayoutPoint flipForWritingModeForChild(const RenderBox* child, const LayoutPoint&) const;
     LayoutUnit flipForWritingMode(LayoutUnit position) const; // The offset is in the block direction (y for horizontal writing modes, x for vertical writing modes).
@@ skipping 244 matching lines @@
         if (UNLIKELY(inlineBoxWrapper() != 0))
             deleteLineBoxWrapper();
     }
 
     ensureRareData().m_inlineBoxWrapper = boxWrapper;
 }
 
 } // namespace blink
 
 #endif // RenderBox_h