Move tray code from ui/chromeos/network/

ui/chromeos/material_design_icon_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 UI_CHROMEOS_MATERIAL_DESIGN_ICON_CONTROLLER_H_
-#define UI_CHROMEOS_MATERIAL_DESIGN_ICON_CONTROLLER_H_
-
-#include "ui/chromeos/ui_chromeos_export.h"
-
-namespace ui {
-namespace md_icon_controller {
-
-// Sets whether or not material design versions of the network icons should
-// be used (WiFi, cellular network, VPN, and network badges). Called by
-// ash::MaterialDesignController upon initialization.
-UI_CHROMEOS_EXPORT void SetUseMaterialDesignNetworkIcons(bool use);
-
-// Returns true if material design versions of the network icons should
-// be used.
-UI_CHROMEOS_EXPORT bool UseMaterialDesignNetworkIcons();
-
-}  // namespace md_icon_controller
-}  // namespace ui
-
-#endif  // UI_CHROMEOS_MATERIAL_DESIGN_ICON_CONTROLLER_H_