[css-grid] "normal" alignment is "start" for replaced elements

third_party/WebKit/Source/core/layout/LayoutGrid.h

 /*
  * Copyright (C) 2011 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 78 matching lines @@
   // TODO(svillar): We need these for the GridTrackSizingAlgorithm. Let's figure
   // it out how to remove this dependency.
   LayoutUnit guttersSize(const Grid&,
                          GridTrackSizingDirection,
                          size_t startLine,
                          size_t span,
                          SizingOperation) const;
   bool cachedHasDefiniteLogicalHeight() const;
   bool isOrthogonalChild(const LayoutBox&) const;
 
+ protected:
+  ItemPosition selfAlignmentNormalBehavior(
+      const LayoutBox* child = nullptr) const override {
+    DCHECK(child);
+    return child->isLayoutReplaced() ? ItemPositionStart : ItemPositionStretch;
+  }
+
  private:
   bool isOfType(LayoutObjectType type) const override {
     return type == LayoutObjectLayoutGrid || LayoutBlock::isOfType(type);
   }
   void computeIntrinsicLogicalWidths(
       LayoutUnit& minLogicalWidth,
       LayoutUnit& maxLogicalWidth) const override;
 
   LayoutUnit computeIntrinsicLogicalContentHeightUsing(
       const Length& logicalHeightLength,
@@ skipping 140 matching lines @@
   LayoutUnit m_maxContentHeight{-1};
 
   Optional<bool> m_hasDefiniteLogicalHeight;
 };
 
 DEFINE_LAYOUT_OBJECT_TYPE_CASTS(LayoutGrid, isLayoutGrid());
 
 }  // namespace blink
 
 #endif  // LayoutGrid_h