[LayoutNG] Fix broken layout while using CSS's writing modes.

third_party/WebKit/Source/core/layout/ng/ng_units.h

Index: third_party/WebKit/Source/core/layout/ng/ng_units.h
diff --git a/third_party/WebKit/Source/core/layout/ng/ng_units.h b/third_party/WebKit/Source/core/layout/ng/ng_units.h
index 80b71628133a5e8aa7d93eccdd3aeac90f65d300..0ad2b1de44d7f423969c22430ce503ea2fd4d2c8 100644
--- a/third_party/WebKit/Source/core/layout/ng/ng_units.h
+++ b/third_party/WebKit/Source/core/layout/ng/ng_units.h
@@ -89,6 +89,16 @@ struct NGPixelSnappedPhysicalRect {
   int height;
 };
 
+// Struct to store physical dimensions, independent of writing mode and
+// direction.
+// See https://drafts.csswg.org/css-writing-modes-3/#abstract-box
+struct NGPhysicalDimensions {
+  LayoutUnit left;
+  LayoutUnit right;
+  LayoutUnit top;
+  LayoutUnit bottom;
+};
+
 // This struct is used for storing margins, borders or padding of a box on all
 // four edges.
 struct NGBoxStrut {