[CSS Grid Layout] Support for justify-items property.

Source/core/rendering/style/StyleRareNonInheritedData.cpp

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. 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.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 71 matching lines @@
     , m_runningOpacityAnimationOnCompositor(false)
     , m_runningTransformAnimationOnCompositor(false)
     , m_runningFilterAnimationOnCompositor(false)
     , m_hasAspectRatio(false)
     , m_effectiveBlendMode(RenderStyle::initialBlendMode())
     , m_touchAction(RenderStyle::initialTouchAction())
     , m_objectFit(RenderStyle::initialObjectFit())
     , m_isolation(RenderStyle::initialIsolation())
     , m_justifyItems(RenderStyle::initialJustifyItems())
     , m_justifyItemsOverflowAlignment(RenderStyle::initialJustifyItemsOverflowAlignment())
-    , m_justifyItemsPositionType(NonLegacyPosition)
+    , m_justifyItemsPositionType(RenderStyle::initialJustifyItemsPositionType())
     , m_justifySelf(RenderStyle::initialJustifySelf())
     , m_justifySelfOverflowAlignment(RenderStyle::initialJustifySelfOverflowAlignment())
     , m_scrollBehavior(RenderStyle::initialScrollBehavior())
     , m_requiresAcceleratedCompositingForExternalReasons(false)
     , m_hasInlineTransform(false)
 {
     m_maskBoxImage.setMaskDefaults();
 }
 
 StyleRareNonInheritedData::StyleRareNonInheritedData(const StyleRareNonInheritedData& o)
@@ skipping 211 matching lines @@
         return false;
     return m_transitions->transitionsMatchForStyleRecalc(*o.m_transitions);
 }
 
 bool StyleRareNonInheritedData::hasFilters() const
 {
     return m_filter.get() && !m_filter->m_operations.isEmpty();
 }
 
 } // namespace blink