Make TextDecorationSkip 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 1246 matching lines @@
   // FIXME: Implement support for 'under left' and 'under right' values.
 
   NOTREACHED();
   return kTextUnderlinePositionAuto;
 }
 
 template <>
 inline TextDecorationSkip CSSIdentifierValue::ConvertTo() const {
   switch (value_id_) {
     case CSSValueObjects:
-      return kTextDecorationSkipObjects;
+      return TextDecorationSkip::kObjects;
     case CSSValueInk:
-      return kTextDecorationSkipInk;
+      return TextDecorationSkip::kInk;
     default:
       break;
   }
 
   NOTREACHED();
-  return kTextDecorationSkipObjects;
+  return TextDecorationSkip::kObjects;
 }
 
 template <>
 inline CSSIdentifierValue::CSSIdentifierValue(ETextSecurity e)
     : CSSValue(kIdentifierClass) {
   switch (e) {
     case ETextSecurity::kNone:
       value_id_ = CSSValueNone;
       break;
     case ETextSecurity::kDisc:
@@ skipping 2006 matching lines @@
     default:
       break;
   }
   NOTREACHED();
   return kContainsNone;
 }
 
 }  // namespace blink
 
 #endif