Remove ash's MaterialDesignController.

ash/material_design/material_design_controller.h

-// Copyright 2016 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_MATERIAL_DESIGN_MATERIAL_DESIGN_CONTROLLER_H_
-#define ASH_MATERIAL_DESIGN_MATERIAL_DESIGN_CONTROLLER_H_
-
-#include "ash/ash_export.h"
-#include "base/macros.h"
-
-namespace ash {
-
-// TODO(estade): deprecated, remove: crbug.com/690957
-class ASH_EXPORT MaterialDesignController {
- public:
-  // Returns true.
-  static bool IsShelfMaterial();
-
-  // Returns true.
-  static bool IsSystemTrayMenuMaterial();
-
- private:
-  // Declarations only. Do not allow construction of an object.
-  MaterialDesignController();
-  ~MaterialDesignController();
-
-  DISALLOW_COPY_AND_ASSIGN(MaterialDesignController);
-};
-
-}  // namespace ash
-
-#endif  // ASH_MATERIAL_DESIGN_MATERIAL_DESIGN_CONTROLLER_H_