Make RubyPosition an enum class.

third_party/WebKit/Source/core/css/CSSPrimitiveValueMappings.h

 /*
  * Copyright (C) 2007 Alexey Proskuryakov <ap@nypop.com>.
  * Copyright (C) 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Torch Mobile Inc. All rights reserved.
  * (http://www.torchmobile.com/)
  * Copyright (C) 2009 Jeff Schiller <codedread@gmail.com>
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ skipping 1562 matching lines @@
   }
 
   NOTREACHED();
   return kTextCombineNone;
 }
 
 template <>
 inline CSSIdentifierValue::CSSIdentifierValue(RubyPosition position)
     : CSSValue(kIdentifierClass) {
   switch (position) {
-    case kRubyPositionBefore:
+    case RubyPosition::kBefore:
       value_id_ = CSSValueBefore;
       break;
-    case kRubyPositionAfter:
+    case RubyPosition::kAfter:
       value_id_ = CSSValueAfter;
       break;
   }
 }
 
 template <>
 inline RubyPosition CSSIdentifierValue::ConvertTo() const {
   switch (value_id_) {
     case CSSValueBefore:
-      return kRubyPositionBefore;
+      return RubyPosition::kBefore;
     case CSSValueAfter:
-      return kRubyPositionAfter;
+      return RubyPosition::kAfter;
     default:
       break;
   }
 
   NOTREACHED();
-  return kRubyPositionBefore;
+  return RubyPosition::kBefore;
 }
 
 template <>
 inline CSSIdentifierValue::CSSIdentifierValue(TextEmphasisPosition position)
     : CSSValue(kIdentifierClass) {
   switch (position) {
     case kTextEmphasisPositionOver:
       value_id_ = CSSValueOver;
       break;
     case kTextEmphasisPositionUnder:
@@ skipping 1705 matching lines @@
     default:
       break;
   }
   NOTREACHED();
   return kContainsNone;
 }
 
 }  // namespace blink
 
 #endif