[CSS Grid Layout] Stretch value for align and justify properties.

Source/core/rendering/style/RenderStyle.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010 Apple Inc. All rights reserved.
  * Copyright (C) 2011 Adobe Systems Incorporated. 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 179 matching lines @@
         return diffPseudoStyles(oldStyle, newStyle);
 
     if (oldStyle->inheritedNotEqual(newStyle)
         || oldStyle->hasExplicitlyInheritedProperties()
         || newStyle->hasExplicitlyInheritedProperties())
         return Inherit;
 
     return NoInherit;
 }
 
-ItemPosition RenderStyle::resolveAlignment(const RenderStyle* parentStyle, const RenderStyle* childStyle)
+ItemPosition RenderStyle::resolveAlignment(const RenderStyle* parentStyle, const RenderStyle* childStyle, ItemPosition resolvedAutoPositionForRenderer)
 {
-    ItemPosition align = childStyle->alignSelf();
     // The auto keyword computes to the parent's align-items computed value, or to "stretch", if not set or "auto".
-    if (align == ItemPositionAuto)
-        align = (parentStyle->alignItems() == ItemPositionAuto) ? ItemPositionStretch : parentStyle->alignItems();
-    return align;
+    if (childStyle->alignSelf() == ItemPositionAuto)
+        return (parentStyle->alignItems() == ItemPositionAuto) ? resolvedAutoPositionForRenderer : parentStyle->alignItems();
+    return childStyle->alignSelf();
+}
+
+ItemPosition RenderStyle::resolveJustification(const RenderStyle* parentStyle, const RenderStyle* childStyle, ItemPosition resolvedAutoPositionForRenderer)
+{
+    if (childStyle->justifySelf() == ItemPositionAuto)
+        return (parentStyle->justifyItems() == ItemPositionAuto) ? resolvedAutoPositionForRenderer : parentStyle->justifyItems();
+    return childStyle->justifySelf();
 }
 
 void RenderStyle::inheritFrom(const RenderStyle* inheritParent, IsAtShadowBoundary isAtShadowBoundary)
 {
     if (isAtShadowBoundary == AtShadowBoundary) {
         // Even if surrounding content is user-editable, shadow DOM should act as a single unit, and not necessarily be editable
         EUserModify currentUserModify = userModify();
         rareInheritedData = inheritParent->rareInheritedData;
         setUserModify(currentUserModify);
     } else
@@ skipping 1537 matching lines @@
         horizontal || includeLogicalRightEdge);
 
     edges[BSLeft] = BorderEdge(borderLeftWidth(),
         visitedDependentColor(CSSPropertyBorderLeftColor),
         borderLeftStyle(),
         borderLeftIsTransparent(),
         !horizontal || includeLogicalLeftEdge);
 }
 
 } // namespace blink