Properly managing overlfow-aligment for inherit and initial.

Source/core/rendering/style/RenderStyle.h

Index: Source/core/rendering/style/RenderStyle.h
diff --git a/Source/core/rendering/style/RenderStyle.h b/Source/core/rendering/style/RenderStyle.h
index 10ef0fab973437da92e3db0a9da1c7ee85343016..00a2fcffe354d0fcb11a8aff26124d9dd34c7bb0 100644
--- a/Source/core/rendering/style/RenderStyle.h
+++ b/Source/core/rendering/style/RenderStyle.h
@@ -1630,6 +1630,7 @@ public:
     static EJustifyContent initialJustifyContent() { return JustifyFlexStart; }
     static ItemPosition initialJustifyItems() { return ItemPositionAuto; }
     static OverflowAlignment initialJustifyItemsOverflowAlignment() { return OverflowAlignmentDefault; }
+    static ItemPositionType initialJustifyItemsPositionType() { return NonLegacyPosition; }
     static ItemPosition initialJustifySelf() { return ItemPositionAuto; }
     static OverflowAlignment initialJustifySelfOverflowAlignment() { return OverflowAlignmentDefault; }
     static int initialMarqueeLoopCount() { return -1; }