Make TextDecoration an enum class.

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

Index: third_party/WebKit/Source/core/style/ComputedStyle.h
diff --git a/third_party/WebKit/Source/core/style/ComputedStyle.h b/third_party/WebKit/Source/core/style/ComputedStyle.h
index 221444d69c8ce5ad0b0c6ca7ba2efdf2f60a16a8..2f750a462132ea5e7577f140c769ee1725823fc8 100644
--- a/third_party/WebKit/Source/core/style/ComputedStyle.h
+++ b/third_party/WebKit/Source/core/style/ComputedStyle.h
@@ -1495,12 +1495,14 @@ class CORE_EXPORT ComputedStyle : public ComputedStyleBase,
 
   // Text decoration properties.
   // text-decoration-line
-  static TextDecoration InitialTextDecoration() { return kTextDecorationNone; }
+  static TextDecoration InitialTextDecoration() {
+    return TextDecoration::kNone;
+  }
   TextDecoration GetTextDecoration() const {
     return static_cast<TextDecoration>(visual_data_->text_decoration);
   }
   void SetTextDecoration(TextDecoration v) {
-    SET_VAR(visual_data_, text_decoration, v);
+    SET_VAR(visual_data_, text_decoration, static_cast<unsigned>(v));
   }
 
   // text-decoration-color