Make TextDecoration an enum class.

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

 /*
  * Copyright (C) 1999 Antti Koivisto (koivisto@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Library General Public License for more details.
  *
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #include "core/style/StyleVisualData.h"
 
 #include "core/style/ComputedStyle.h"
 
 namespace blink {
 
 StyleVisualData::StyleVisualData()
     : has_auto_clip(true),
-      text_decoration(ComputedStyle::InitialTextDecoration()),
+      text_decoration(
+          static_cast<unsigned>(ComputedStyle::InitialTextDecoration())),
       zoom_(ComputedStyle::InitialZoom()) {}
 
 StyleVisualData::~StyleVisualData() {}
 
 StyleVisualData::StyleVisualData(const StyleVisualData& o)
     : RefCounted<StyleVisualData>(),
       clip(o.clip),
       has_auto_clip(o.has_auto_clip),
       text_decoration(o.text_decoration),
       zoom_(o.zoom_) {}
 
 }  // namespace blink