[CSS Grid Layout] Avoid using StyleAdjuster to resolve 'auto' values.

Source/core/style/ComputedStyle.cpp

Index: Source/core/style/ComputedStyle.cpp
diff --git a/Source/core/style/ComputedStyle.cpp b/Source/core/style/ComputedStyle.cpp
index c01ddf928a2c652f6b556d64357ec39ae634dc64..873c608aa44bc2cc8bc740c02882ddbc4326e3f7 100644
--- a/Source/core/style/ComputedStyle.cpp
+++ b/Source/core/style/ComputedStyle.cpp
@@ -177,9 +177,7 @@ StyleRecalcChange ComputedStyle::stylePropagationDiff(const ComputedStyle* oldSt
         || oldStyle->hasPseudoStyle(FIRST_LETTER) != newStyle->hasPseudoStyle(FIRST_LETTER)
         || oldStyle->columnSpan() != newStyle->columnSpan()
         || !oldStyle->contentDataEquivalent(newStyle)
-        || oldStyle->hasTextCombine() != newStyle->hasTextCombine()
-        || oldStyle->justifyItems() != newStyle->justifyItems()
-        || oldStyle->alignItems() != newStyle->alignItems())
+        || oldStyle->hasTextCombine() != newStyle->hasTextCombine())
         return Reattach;
 
     if (oldStyle->inheritedNotEqual(*newStyle))
@@ -194,7 +192,7 @@ StyleRecalcChange ComputedStyle::stylePropagationDiff(const ComputedStyle* oldSt
     return NoInherit;
 }
 
-ItemPosition ComputedStyle::resolveAlignment(const ComputedStyle& parentStyle, const ComputedStyle& childStyle, ItemPosition resolvedAutoPositionForLayoutObject)
+ItemPosition ComputedStyle::resolvedAlignSelfPosition(const ComputedStyle& parentStyle, const ComputedStyle& childStyle, ItemPosition resolvedAutoPositionForLayoutObject)
 {
     // The auto keyword computes to the parent's align-items computed value, or to "stretch", if not set or "auto".
     if (childStyle.alignSelfPosition() == ItemPositionAuto)
@@ -202,13 +200,58 @@ ItemPosition ComputedStyle::resolveAlignment(const ComputedStyle& parentStyle, c
     return childStyle.alignSelfPosition();
 }
 
-ItemPosition ComputedStyle::resolveJustification(const ComputedStyle& parentStyle, const ComputedStyle& childStyle, ItemPosition resolvedAutoPositionForLayoutObject)
+OverflowAlignment ComputedStyle::resolvedAlignSelfOverflow(const ComputedStyle& parentStyle, const ComputedStyle& childStyle)
 {
+    // It computes to the parent's align-items computed value if "auto".
+    return (childStyle.alignSelfPosition() == ItemPositionAuto) ? parentStyle.alignItemsOverflowAlignment() : childStyle.alignSelfOverflowAlignment();
+}
+
+ItemPosition ComputedStyle::resolvedJustifySelfPosition(const ComputedStyle& parentStyle, const ComputedStyle& childStyle, ItemPosition resolvedAutoPositionForLayoutObject)
+{
+    // The auto keyword computes to the parent's justify-items computed value, or to "stretch", if not set or "auto".
     if (childStyle.justifySelfPosition() == ItemPositionAuto)
         return (parentStyle.justifyItemsPosition() == ItemPositionAuto) ? resolvedAutoPositionForLayoutObject : parentStyle.justifyItemsPosition();
     return childStyle.justifySelfPosition();
 }
 
+OverflowAlignment ComputedStyle::resolvedJustifySelfOverflow(const ComputedStyle& parentStyle, const ComputedStyle& childStyle)
+{
+    // It computes to the parent's justify-items computed value if "auto".
+    return (childStyle.justifySelfPosition() == ItemPositionAuto) ? parentStyle.justifyItemsOverflowAlignment() : childStyle.justifySelfOverflowAlignment();
+}
+
+ContentPosition ComputedStyle::resolvedAlignContentPosition() const
+{
+    const StyleContentAlignmentData& align = alignContent();
+    if (align.position() != ContentPositionAuto || align.distribution() != ContentDistributionDefault)
+        return align.position();
+    // 'auto' computes to 'stretch' for flexbox, hence it's managed by distribution().
+    return isDisplayFlexibleBox() ? ContentPositionAuto : ContentPositionStart;
+}
+
+ContentDistributionType ComputedStyle::resolvedAlignContentDistribution() const
+{
+    const StyleContentAlignmentData& align = alignContent();
+    if (align.position() != ContentPositionAuto || align.distribution() != ContentDistributionDefault)
+        return align.distribution();
+    return isDisplayFlexibleBox() ? ContentDistributionStretch : ContentDistributionDefault;
+}
+
+ContentPosition ComputedStyle::resolvedJustifyContentPosition() const
+{
+    const StyleContentAlignmentData& justify = justifyContent();
+    if (justify.position() != ContentPositionAuto || justify.distribution() != ContentDistributionDefault)
+        return justify.position();
+    // 'auto' computes to 'stretch' for flexbox, but since flexing in the main axis is controlled by flex, it behaves as flex-start.
+    return isDisplayFlexibleBox() ? ContentPositionFlexStart : ContentPositionStart;
+}
+
+ContentDistributionType ComputedStyle::resolvedJustifyContentDistribution() const
+{
+    // even that 'auto' computes to 'stretch' for flexbox it behaves as flex-start, hence it's managed by position().
+    return justifyContentDistribution();
+}
+
 void ComputedStyle::inheritFrom(const ComputedStyle& inheritParent, IsAtShadowBoundary isAtShadowBoundary)
 {
     if (isAtShadowBoundary == AtShadowBoundary) {
@@ -468,12 +511,16 @@ bool ComputedStyle::diffNeedsFullLayoutAndPaintInvalidation(const ComputedStyle&
             || rareNonInheritedData->m_wrapThrough != other.rareNonInheritedData->m_wrapThrough
             || rareNonInheritedData->m_shapeMargin != other.rareNonInheritedData->m_shapeMargin
             || rareNonInheritedData->m_order != other.rareNonInheritedData->m_order
-            || rareNonInheritedData->m_grid.get() != other.rareNonInheritedData->m_grid.get()
-            || rareNonInheritedData->m_gridItem.get() != other.rareNonInheritedData->m_gridItem.get()
             || rareNonInheritedData->m_textCombine != other.rareNonInheritedData->m_textCombine
             || rareNonInheritedData->hasFilters() != other.rareNonInheritedData->hasFilters())
             return true;
 
+        if ((rareNonInheritedData->m_grid.get() != other.rareNonInheritedData->m_grid.get()
+            && *rareNonInheritedData->m_grid.get() != *other.rareNonInheritedData->m_grid.get())
+            || (rareNonInheritedData->m_gridItem.get() != other.rareNonInheritedData->m_gridItem.get()
+                && *rareNonInheritedData->m_gridItem.get() != *other.rareNonInheritedData->m_gridItem.get()))
+            return true;
+
         if (rareNonInheritedData->m_deprecatedFlexibleBox.get() != other.rareNonInheritedData->m_deprecatedFlexibleBox.get()
             && *rareNonInheritedData->m_deprecatedFlexibleBox.get() != *other.rareNonInheritedData->m_deprecatedFlexibleBox.get())
             return true;