CustomButton cleanup: make protected members private, create accessors

ui/views/controls/scrollbar/kennedy_scroll_bar.h

-// Copyright (c) 2013 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_VIEWS_CONTROLS_SCROLLBAR_KENNEDY_SCROLL_BAR_H_
-#define UI_VIEWS_CONTROLS_SCROLLBAR_KENNEDY_SCROLL_BAR_H_
-
-#include "ui/views/controls/scrollbar/base_scroll_bar.h"
-
-namespace views {
-
-// The scrollbar of kennedy style. Transparent track and grey rectangle
-// thumb. Right now it doesn't have the way to share the background,
-// so it will accept the background color instead.
-class VIEWS_EXPORT KennedyScrollBar : public BaseScrollBar {
- public:
-  explicit KennedyScrollBar(bool horizontal);
-  ~KennedyScrollBar() override;
-
- protected:
-  // BaseScrollBar overrides:
-  gfx::Rect GetTrackBounds() const override;
-
-  // ScrollBar overrides:
-  int GetLayoutSize() const override;
-
-  // View overrides:
-  gfx::Size GetPreferredSize() const override;
-  void Layout() override;
-  void OnPaint(gfx::Canvas* canvas) override;
-
- private:
-  DISALLOW_COPY_AND_ASSIGN(KennedyScrollBar);
-};
-
-}  // namespace views
-
-#endif  // UI_VIEWS_CONTROLS_SCROLLBAR_KENNEDY_SCROLL_BAR_H_