Sync ui/events to chromium @ https://codereview.chromium.org/1210203002

ui/events/input_device_event_observer.h

Index: ui/events/input_device_event_observer.h
diff --git a/ui/events/input_device_event_observer.h b/ui/events/input_device_event_observer.h
deleted file mode 100644
index 679f1f4eb70b83f9a4ec7a0ba595ddae06d131f5..0000000000000000000000000000000000000000
--- a/ui/events/input_device_event_observer.h
+++ /dev/null
@@ -1,20 +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_INPUT_DEVICE_EVENT_OBSERVER_H_
-#define UI_EVENTS_INPUT_DEVICE_EVENT_OBSERVER_H_
-
-namespace ui {
-
-// DeviceDataManager observer used to announce input hotplug events.
-class InputDeviceEventObserver {
- public:
-  virtual ~InputDeviceEventObserver() {}
-
-  virtual void OnInputDeviceConfigurationChanged() = 0;
-};
-
-}  // namespace ui
-
-#endif  // UI_EVENTS_INPUT_DEVICE_EVENT_OBSERVER_H_