[CSS Grid Layout] Do not stretch always grid items with auto width

Source/core/layout/LayoutGrid.cpp

Index: Source/core/layout/LayoutGrid.cpp
diff --git a/Source/core/layout/LayoutGrid.cpp b/Source/core/layout/LayoutGrid.cpp
index bbc127fec4d4b4a5055d2b86284633e04ea4c9ea..363e7f0a95f8b97aa67c686c04cea3e0f3f3a804 100644
--- a/Source/core/layout/LayoutGrid.cpp
+++ b/Source/core/layout/LayoutGrid.cpp
@@ -1275,7 +1275,7 @@ void LayoutGrid::layoutGridItems()
         // Stretching logic might force a child layout, so we need to run it before the layoutIfNeeded
         // call to avoid unnecessary relayouts. This might imply that child margins, needed to correctly
         // determine the available space before stretching, are not set yet.
-        applyStretchAlignmentToChildIfNeeded(*child, overrideContainingBlockContentLogicalHeight);
+        applyStretchAlignmentToChildIfNeeded(*child);
 
         child->layoutIfNeeded();
 
@@ -1458,6 +1458,11 @@ bool LayoutGrid::allowedToStretchLogicalHeightForChild(const LayoutBox& child) c
     return child.style()->logicalHeight().isAuto() && !child.style()->marginBeforeUsing(style()).isAuto() && !child.style()->marginAfterUsing(style()).isAuto();
 }
 
+bool LayoutGrid::allowedToStretchLogicalWidthForChild(const LayoutBox& child) const
+{
+    return child.style()->logicalWidth().isAuto() && !child.style()->marginStartUsing(style()).isAuto() && !child.style()->marginEndUsing(style()).isAuto();
+}
+
 // FIXME: This logic is shared by LayoutFlexibleBox, so it should be moved to LayoutBox.
 bool LayoutGrid::needToStretchChildLogicalHeight(const LayoutBox& child) const
 {
@@ -1523,18 +1528,27 @@ LayoutUnit LayoutGrid::availableAlignmentSpaceForChildBeforeStretching(LayoutUni
 }
 
 // FIXME: This logic is shared by LayoutFlexibleBox, so it should be moved to LayoutBox.
-void LayoutGrid::applyStretchAlignmentToChildIfNeeded(LayoutBox& child, LayoutUnit gridAreaBreadthForChild)
+void LayoutGrid::applyStretchAlignmentToChildIfNeeded(LayoutBox& child)
 {
-    if (!allowedToStretchLogicalHeightForChild(child) || ComputedStyle::resolveAlignment(styleRef(), child.styleRef(), ItemPositionStretch) != ItemPositionStretch) {
-        child.clearOverrideLogicalContentHeight();
-        return;
+    child.clearOverrideSize();
+
+    if (!allowedToStretchLogicalWidthForChild(child) || ComputedStyle::resolveJustification(styleRef(), child.styleRef(), ItemPositionStretch) != ItemPositionStretch) {
+        if (child.style()->logicalWidth().isAuto()) {
+            LayoutUnit childPreferredWidth = child.maxPreferredLogicalWidth();
+            child.setOverrideLogicalContentWidth(childPreferredWidth - child.borderAndPaddingLogicalWidth());
+            if (childPreferredWidth != child.logicalWidth())
+                child.setNeedsLayout(LayoutInvalidationReason::GridChanged);
+        }
     }
 
+    if (!allowedToStretchLogicalHeightForChild(child) || ComputedStyle::resolveAlignment(styleRef(), child.styleRef(), ItemPositionStretch) != ItemPositionStretch)
+        return;
+
     bool hasOrthogonalWritingMode = child.isHorizontalWritingMode() != isHorizontalWritingMode();
     // FIXME: If the child has orthogonal flow, then it already has an override height set, so use it.
     // FIXME: grid track sizing and positioning do not support orthogonal modes yet.
     if (!hasOrthogonalWritingMode) {
-        LayoutUnit stretchedLogicalHeight = availableAlignmentSpaceForChildBeforeStretching(gridAreaBreadthForChild, child);
+        LayoutUnit stretchedLogicalHeight = availableAlignmentSpaceForChildBeforeStretching(child.overrideContainingBlockContentLogicalHeight(), child);
         LayoutUnit desiredLogicalHeight = child.constrainLogicalHeightByMinMax(stretchedLogicalHeight, -1);
 
         // FIXME: Can avoid laying out here in some cases. See https://webkit.org/b/87905.