Partial revert of https://codereview.chromium.org/1911973002/

ui/native_theme/native_theme_aurawin.h

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef UI_NATIVE_THEME_NATIVE_THEME_AURAWIN_H_
-#define UI_NATIVE_THEME_NATIVE_THEME_AURAWIN_H_
-
-#include "base/compiler_specific.h"
-#include "base/macros.h"
-#include "ui/native_theme/native_theme_aura.h"
-
-namespace ui {
-
-// Aura implementation of native theme support.
-class NATIVE_THEME_EXPORT NativeThemeAuraWin : public NativeThemeAura {
- public:
-  static NativeThemeAuraWin* instance();
-
- private:
-  NativeThemeAuraWin();
-  ~NativeThemeAuraWin() override;
-
-  // Overridden from NativeThemeBase:
-  gfx::Size GetPartSize(Part part,
-                        State state,
-                        const ExtraParams& extra) const override;
-  void Paint(SkCanvas* canvas,
-             Part part,
-             State state,
-             const gfx::Rect& rect,
-             const ExtraParams& extra) const override;
-  DISALLOW_COPY_AND_ASSIGN(NativeThemeAuraWin);
-};
-
-}  // namespace ui
-
-#endif  // UI_NATIVE_THEME_NATIVE_THEME_AURAWIN_H_