mash: Add SystemTrayClient interface, use to show date settings

chrome/browser/ui/ash/system_tray_controller_mus.h

Index: chrome/browser/ui/ash/system_tray_controller_mus.h
diff --git a/chrome/browser/ui/ash/system_tray_controller_mus.h b/chrome/browser/ui/ash/system_tray_controller_mus.h
deleted file mode 100644
index b194f7c4f3fd265edf139fd67d2b6e1cfbd2c02f..0000000000000000000000000000000000000000
--- a/chrome/browser/ui/ash/system_tray_controller_mus.h
+++ /dev/null
@@ -1,27 +0,0 @@
-// 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 CHROME_BROWSER_UI_ASH_SYSTEM_TRAY_CONTROLLER_MUS_H_
-#define CHROME_BROWSER_UI_ASH_SYSTEM_TRAY_CONTROLLER_MUS_H_
-
-#include "ash/public/interfaces/system_tray.mojom.h"
-#include "base/macros.h"
-#include "chrome/browser/chromeos/system/system_clock_observer.h"
-
-// Controls chrome's interaction with the ash system tray menu.
-class SystemTrayControllerMus : public chromeos::system::SystemClockObserver {
- public:
-  SystemTrayControllerMus();
-  ~SystemTrayControllerMus() override;
-
- private:
-  // chromeos::system::SystemClockObserver:
-  void OnSystemClockChanged(chromeos::system::SystemClock* clock) override;
-
-  ash::mojom::SystemTrayPtr system_tray_;
-
-  DISALLOW_COPY_AND_ASSIGN(SystemTrayControllerMus);
-};
-
-#endif  // CHROME_BROWSER_UI_ASH_SYSTEM_TRAY_CONTROLLER_MUS_H_