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

ui/events/ozone/device/udev/scoped_udev.h

Index: ui/events/ozone/device/udev/scoped_udev.h
diff --git a/ui/events/ozone/evdev/scoped_udev.h b/ui/events/ozone/device/udev/scoped_udev.h
similarity index 89%
rename from ui/events/ozone/evdev/scoped_udev.h
rename to ui/events/ozone/device/udev/scoped_udev.h
index 21063e3225d4c633055dfd9718757e5d90aab008..2d02bb3465eb23d979e9aafc91073327e09c82d9 100644
--- a/ui/events/ozone/evdev/scoped_udev.h
+++ b/ui/events/ozone/device/udev/scoped_udev.h
@@ -2,8 +2,8 @@
 // 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_DEVICE_UDEV_SCOPED_UDEV_H_
+#define UI_EVENTS_OZONE_DEVICE_UDEV_SCOPED_UDEV_H_
 
 #include <libudev.h>
 
@@ -47,4 +47,4 @@ typedef scoped_ptr<struct udev_monitor, UdevMonitorDeleter> scoped_udev_monitor;
 
 }  // namespace ui
 
-#endif  // UI_EVENTS_OZONE_EVDEV_SCOPED_UDEV_H_
+#endif  // UI_EVENTS_OZONE_DEVICE_UDEV_SCOPED_UDEV_H_