Remove FixedSizedScrollView.

ash/common/system/tray/fixed_sized_scroll_view.h

-// Copyright 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 ASH_COMMON_SYSTEM_TRAY_FIXED_SIZED_SCROLL_VIEW_H_
-#define ASH_COMMON_SYSTEM_TRAY_FIXED_SIZED_SCROLL_VIEW_H_
-
-#include "base/macros.h"
-#include "ui/views/controls/scroll_view.h"
-
-namespace ash {
-
-// A custom scroll-view that has a specified dimension.
-// TODO(estade): can we get rid of this class? In MD, it hardly differs in
-// behavior from ScrollView.
-class FixedSizedScrollView : public views::ScrollView {
- public:
-  FixedSizedScrollView();
-  ~FixedSizedScrollView() override;
-
-  void SetContentsView(views::View* view);
-
-  // Change the fixed size of the view. Invalidates the layout (by calling
-  // PreferredSizeChanged()).
-  void SetFixedSize(const gfx::Size& size);
-
-  void set_fixed_size(const gfx::Size& size);
-
-  // Overridden from views::View:
-  gfx::Size GetPreferredSize() const override;
-  void Layout() override;
-
- protected:
-  // Overridden from views::View:
-  void OnBoundsChanged(const gfx::Rect& previous_bounds) override;
-
- private:
-  gfx::Size fixed_size_;
-
-  DISALLOW_COPY_AND_ASSIGN(FixedSizedScrollView);
-};
-
-}  // namespace ash
-
-#endif  // ASH_COMMON_SYSTEM_TRAY_FIXED_SIZED_SCROLL_VIEW_H_