It is time.

ui/events/ozone/device/device_event_observer.h

Index: ui/events/ozone/device/device_event_observer.h
diff --git a/ui/events/ozone/device/device_event_observer.h b/ui/events/ozone/device/device_event_observer.h
deleted file mode 100644
index 7ad2f4966c11217fbd49bc8d1452e8825e702407..0000000000000000000000000000000000000000
--- a/ui/events/ozone/device/device_event_observer.h
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright 2014 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_EVENTS_OZONE_DEVICE_EVENT_OBSERVER_H_
-#define UI_EVENTS_OZONE_DEVICE_EVENT_OBSERVER_H_
-
-#include "ui/events/ozone/events_ozone_export.h"
-
-namespace ui {
-
-class DeviceEvent;
-
-class EVENTS_OZONE_EXPORT DeviceEventObserver {
- public:
-  virtual ~DeviceEventObserver() {}
-
-  virtual void OnDeviceEvent(const DeviceEvent& event) = 0;
-};
-
-}  // namespace ui
-
-#endif  // UI_EVENTS_OZONE_DEVICE_EVENT_OBSERVER_H_
-