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

ui/events/ozone/scoped_udev.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_EVDEV_SCOPED_UDEV_H_
-#define UI_EVENTS_OZONE_EVDEV_SCOPED_UDEV_H_
+#ifndef UI_EVENTS_OZONE_SCOPED_UDEV_H_
+#define UI_EVENTS_OZONE_SCOPED_UDEV_H_
 
 #include <libudev.h>
 
 #include "base/memory/scoped_ptr.h"
 
 // This file enables management of udev object references using scoped_ptr<> by
 // associating a custom deleter that drops the reference rather than deleting.
 
 namespace ui {
 
@@ skipping 23 matching lines @@
 // Scoped struct udev_monitor.
 struct UdevMonitorDeleter {
   void operator()(struct udev_monitor* udev_monitor) {
     udev_monitor_unref(udev_monitor);
   }
 };
 typedef scoped_ptr<struct udev_monitor, UdevMonitorDeleter> scoped_udev_monitor;
 
 }  // namespace ui
 
-#endif  // UI_EVENTS_OZONE_EVDEV_SCOPED_UDEV_H_
+#endif  // UI_EVENTS_OZONE_SCOPED_UDEV_H_