Make TextDecoration an enum class.

third_party/WebKit/Source/core/style/AppliedTextDecoration.cpp

Index: third_party/WebKit/Source/core/style/AppliedTextDecoration.cpp
diff --git a/third_party/WebKit/Source/core/style/AppliedTextDecoration.cpp b/third_party/WebKit/Source/core/style/AppliedTextDecoration.cpp
index 263bbe5d2f34506cfc77820cdc8b98d967443d54..c1b4b9a1c2764377d45da91c922659ff36e15066 100644
--- a/third_party/WebKit/Source/core/style/AppliedTextDecoration.cpp
+++ b/third_party/WebKit/Source/core/style/AppliedTextDecoration.cpp
@@ -9,7 +9,7 @@ namespace blink {
 AppliedTextDecoration::AppliedTextDecoration(TextDecoration line,
                                              TextDecorationStyle style,
                                              Color color)
-    : lines_(line), style_(style), color_(color) {}
+    : lines_(static_cast<unsigned>(line)), style_(style), color_(color) {}
 
 bool AppliedTextDecoration::operator==(const AppliedTextDecoration& o) const {
   return color_ == o.color_ && lines_ == o.lines_ && style_ == o.style_;