[LayoutNG] Implement more text-align values and BiDi base direction

third_party/WebKit/Source/platform/text/TextDirection.h

 /*
  * Copyright (C) 2003, 2006 Apple Computer, 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 30 matching lines @@
 // http://unicode.org/reports/tr9/
 enum class TextDirection : uint8_t { kLtr = 0, kRtl = 1 };
 
 inline bool IsLtr(TextDirection direction) {
   return direction == TextDirection::kLtr;
 }
 
 inline bool IsRtl(TextDirection direction) {
   return direction != TextDirection::kLtr;
 }
+
+inline TextDirection DirectionFromLevel(unsigned level) {
+  return level & 1 ? TextDirection::kRtl : TextDirection::kLtr;
+}
 }
 
 #endif