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

ui/events/devices/input_device_event_observer.h

Index: ui/events/devices/input_device_event_observer.h
diff --git a/ui/events/devices/input_device_event_observer.h b/ui/events/devices/input_device_event_observer.h
new file mode 100644
index 0000000000000000000000000000000000000000..fa02d5a9d6ae27cc07a098b9946d7662e3098b6d
--- /dev/null
+++ b/ui/events/devices/input_device_event_observer.h
@@ -0,0 +1,29 @@
+// 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_DEVICES_INPUT_DEVICE_EVENT_OBSERVER_H_
+#define UI_EVENTS_DEVICES_INPUT_DEVICE_EVENT_OBSERVER_H_
+
+#include "ui/events/devices/events_devices_export.h"
+
+namespace ui {
+
+// DeviceDataManager observer used to announce input hotplug events.
+class EVENTS_DEVICES_EXPORT InputDeviceEventObserver {
+ public:
+  virtual ~InputDeviceEventObserver() {}
+
+  virtual void OnKeyboardDeviceConfigurationChanged() {}
+  virtual void OnTouchscreenDeviceConfigurationChanged() {}
+  virtual void OnMouseDeviceConfigurationChanged() {}
+  virtual void OnTouchpadDeviceConfigurationChanged() {}
+  virtual void OnDeviceListsComplete() {}
+
+ protected:
+  InputDeviceEventObserver() {}
+};
+
+}  // namespace ui
+
+#endif  // UI_EVENTS_DEVICES_INPUT_DEVICE_EVENT_OBSERVER_H_