Make TextUnderlinePosition an enum class.

This patch makes TextUnderlinePosition an enum class for better type
safety.

BUG=684966
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_layout_tests_slimming_paint_v2

Review-Url: https://codereview.chromium.org/2909423002
Cr-Commit-Position: refs/heads/master@{#475815}

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

@@ -1146,10 +1146,10 @@ template <>
 inline CSSIdentifierValue::CSSIdentifierValue(TextUnderlinePosition e)
     : CSSValue(kIdentifierClass) {
   switch (e) {
-    case kTextUnderlinePositionAuto:
+    case TextUnderlinePosition::kAuto:
       value_id_ = CSSValueAuto;
       break;
-    case kTextUnderlinePositionUnder:
+    case TextUnderlinePosition::kUnder:
       value_id_ = CSSValueUnder;
       break;
   }
@@ -1161,9 +1161,9 @@ template <>
 inline TextUnderlinePosition CSSIdentifierValue::ConvertTo() const {
   switch (value_id_) {
     case CSSValueAuto:
-      return kTextUnderlinePositionAuto;
+      return TextUnderlinePosition::kAuto;
     case CSSValueUnder:
-      return kTextUnderlinePositionUnder;
+      return TextUnderlinePosition::kUnder;
     default:
       break;
   }
@@ -1171,7 +1171,7 @@ inline TextUnderlinePosition CSSIdentifierValue::ConvertTo() const {
   // FIXME: Implement support for 'under left' and 'under right' values.
 
   NOTREACHED();
-  return kTextUnderlinePositionAuto;
+  return TextUnderlinePosition::kAuto;
 }
 
 template <>

third_party/WebKit/Source/core/css/CSSProperties.json5

@@ -2148,7 +2148,7 @@
       runtime_flag: "CSS3TextDecorations",
       field_template: "storage_only",
       type_name: "TextUnderlinePosition",
-      default_value: "kTextUnderlinePositionAuto",
+      default_value: "TextUnderlinePosition::kAuto",
       field_size: 1,
       field_group: "rare-inherited",
     },

third_party/WebKit/Source/core/paint/TextPainterBase.cpp

@@ -199,9 +199,9 @@ static ResolvedUnderlinePosition ResolveUnderlinePosition(
   switch (baseline_type) {
     case kAlphabeticBaseline:
       switch (style.GetTextUnderlinePosition()) {
-        case kTextUnderlinePositionAuto:
+        case TextUnderlinePosition::kAuto:
           return ResolvedUnderlinePosition::kRoman;
-        case kTextUnderlinePositionUnder:
+        case TextUnderlinePosition::kUnder:
           return ResolvedUnderlinePosition::kUnder;
       }
       break;

third_party/WebKit/Source/core/style/ComputedStyle.h

@@ -1475,14 +1475,15 @@ class CORE_EXPORT ComputedStyle : public ComputedStyleBase<ComputedStyle>,
 
   // text-underline-position
   static TextUnderlinePosition InitialTextUnderlinePosition() {
-    return kTextUnderlinePositionAuto;
+    return TextUnderlinePosition::kAuto;
   }
   TextUnderlinePosition GetTextUnderlinePosition() const {
     return static_cast<TextUnderlinePosition>(
         rare_inherited_data_->text_underline_position_);
   }
   void SetTextUnderlinePosition(TextUnderlinePosition v) {
-    SET_VAR(rare_inherited_data_, text_underline_position_, v);
+    SET_VAR(rare_inherited_data_, text_underline_position_,
+            static_cast<unsigned>(v));
   }
 
   // text-decoration-skip

third_party/WebKit/Source/core/style/ComputedStyleConstants.h

@@ -248,10 +248,10 @@ inline TextDecorationSkip& operator|=(TextDecorationSkip& a,
   return a = a | b;
 }
 
-enum TextUnderlinePosition {
+enum class TextUnderlinePosition {
   // FIXME: Implement support for 'under left' and 'under right' values.
-  kTextUnderlinePositionAuto,
-  kTextUnderlinePositionUnder
+  kAuto,
+  kUnder
 };
 
 enum ETransformStyle3D { kTransformStyle3DFlat, kTransformStyle3DPreserve3D };