Refactor Udev device support in Ozone and add a DRM hotplug monitor

ui/events/ozone/device/device_manager_manual.h

+// 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_DEVICE_MANAGER_MANUAL_H_
+#define UI_EVENTS_OZONE_DEVICE_DEVICE_MANAGER_MANUAL_H_
+
+#include "base/macros.h"
+#include "ui/events/ozone/device/device_manager.h"
+
+namespace ui {
+
+class DeviceManagerManual : public DeviceManager {
+ public:
+  DeviceManagerManual();
+  virtual ~DeviceManagerManual();
+
+ private:
+  // DeviceManager overrides:
+  virtual void ScanDevices(DeviceEventObserver* observer) OVERRIDE;
+  virtual void AddObserver(DeviceEventObserver* observer) OVERRIDE;
+  virtual void RemoveObserver(DeviceEventObserver* observer) OVERRIDE;
+
+  DISALLOW_COPY_AND_ASSIGN(DeviceManagerManual);
+};
+
+}  // namespace ui
+
+#endif  // UI_EVENTS_OZONE_DEVICE_DEVICE_MANAGER_MANUAL_H_