[CSS Grid Layout] Don't resolve align-self and justify-self properties

Source/core/css/CSSComputedStyleDeclaration.cpp

Index: Source/core/css/CSSComputedStyleDeclaration.cpp
diff --git a/Source/core/css/CSSComputedStyleDeclaration.cpp b/Source/core/css/CSSComputedStyleDeclaration.cpp
index d2aae7dff888c26e3357ccb41d925bf2ef766978..3c150c71a26cb533a8860e281119ccf099fd29d2 100644
--- a/Source/core/css/CSSComputedStyleDeclaration.cpp
+++ b/Source/core/css/CSSComputedStyleDeclaration.cpp
@@ -55,6 +55,7 @@
 #include "core/css/resolver/StyleResolver.h"
 #include "core/dom/Document.h"
 #include "core/dom/ExceptionCode.h"
+#include "core/dom/NodeRenderingTraversal.h"
 #include "core/dom/PseudoElement.h"
 #include "core/rendering/RenderBox.h"
 #include "core/rendering/RenderGrid.h"
@@ -1536,15 +1537,16 @@ Node* CSSComputedStyleDeclaration::styledNode() const
     return m_node.get();
 }
 
-static ItemPosition resolveAlignmentAuto(ItemPosition position, Node* element)
+static void resolveAlignment(Node* styledNode, ItemPosition& position, OverflowAlignment& overflow)
 {
-    if (position != ItemPositionAuto)
-        return position;
-
-    bool isFlexOrGrid = element && element->computedStyle()
-        && element->computedStyle()->isDisplayFlexibleOrGridBox();
-
-    return isFlexOrGrid ? ItemPositionStretch : ItemPositionStart;
+    if (position == ItemPositionAuto) {
+        if (Node* parent = NodeRenderingTraversal::parent(styledNode)) {
+            if (RenderStyle* parentStyle = parent->computedStyle()) {
+                position = parentStyle->alignItems();
+                overflow = parentStyle->alignItemsOverflowAlignment();
+            }
+        }
+    }
 }
 
 static PassRefPtrWillBeRawPtr<CSSValueList> valueForItemPositionWithOverflowAlignment(ItemPosition itemPosition, OverflowAlignment overflowAlignment, ItemPositionType positionType)
@@ -1828,9 +1830,13 @@ PassRefPtrWillBeRawPtr<CSSValue> CSSComputedStyleDeclaration::getPropertyCSSValu
         case CSSPropertyAlignContent:
             return cssValuePool().createValue(style->alignContent());
         case CSSPropertyAlignItems:
-            return valueForItemPositionWithOverflowAlignment(resolveAlignmentAuto(style->alignItems(), styledNode), style->alignItemsOverflowAlignment(), NonLegacyPosition);
-        case CSSPropertyAlignSelf:
-            return valueForItemPositionWithOverflowAlignment(resolveAlignmentAuto(style->alignSelf(), styledNode->parentNode()), style->alignSelfOverflowAlignment(), NonLegacyPosition);
+            return valueForItemPositionWithOverflowAlignment(style->alignItems(), style->alignItemsOverflowAlignment(), NonLegacyPosition);
+        case CSSPropertyAlignSelf: {
+            ItemPosition alignSelf = style->alignSelf();
+            OverflowAlignment overflow = style->alignSelfOverflowAlignment();
+            resolveAlignment(styledNode, alignSelf, overflow);
+            return valueForItemPositionWithOverflowAlignment(alignSelf, overflow, NonLegacyPosition);
+        }
         case CSSPropertyFlex:
             return valuesForShorthandProperty(flexShorthand());
         case CSSPropertyFlexBasis:
@@ -1998,9 +2004,13 @@ PassRefPtrWillBeRawPtr<CSSValue> CSSComputedStyleDeclaration::getPropertyCSSValu
         case CSSPropertyIsolation:
             return cssValuePool().createValue(style->isolation());
         case CSSPropertyJustifyItems:
-            return valueForItemPositionWithOverflowAlignment(resolveAlignmentAuto(style->justifyItems(), styledNode), style->justifyItemsOverflowAlignment(), style->justifyItemsPositionType());
-        case CSSPropertyJustifySelf:
-            return valueForItemPositionWithOverflowAlignment(resolveAlignmentAuto(style->justifySelf(), styledNode->parentNode()), style->justifySelfOverflowAlignment(), NonLegacyPosition);
+            return valueForItemPositionWithOverflowAlignment(style->justifyItems(), style->justifyItemsOverflowAlignment(), style->justifyItemsPositionType());
+        case CSSPropertyJustifySelf: {
+            ItemPosition justifySelf = style->justifySelf();
+            OverflowAlignment overflow = style->justifySelfOverflowAlignment();
+            resolveAlignment(styledNode, justifySelf, overflow);
+            return valueForItemPositionWithOverflowAlignment(justifySelf, overflow, NonLegacyPosition);
+        }
         case CSSPropertyLeft:
             return valueForPositionOffset(*style, CSSPropertyLeft, renderer);
         case CSSPropertyLetterSpacing: