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

ui/ozone/platform/dri/chromeos/native_display_delegate_dri.h

Index: ui/ozone/platform/dri/chromeos/native_display_delegate_dri.h
diff --git a/ui/ozone/platform/dri/chromeos/native_display_delegate_dri.h b/ui/ozone/platform/dri/chromeos/native_display_delegate_dri.h
index db5b5eb2b7328c9ac2a6ac6540fe7d3fb31603e6..a2a0888747eab8cecc68853f37e39dd8ebbbc020 100644
--- a/ui/ozone/platform/dri/chromeos/native_display_delegate_dri.h
+++ b/ui/ozone/platform/dri/chromeos/native_display_delegate_dri.h
@@ -5,18 +5,21 @@
 #ifndef UI_OZONE_PLATFORM_DRI_CHROMEOS_NATIVE_DISPLAY_DELEGATE_DRI_H_
 #define UI_OZONE_PLATFORM_DRI_CHROMEOS_NATIVE_DISPLAY_DELEGATE_DRI_H_
 
+#include "base/memory/scoped_ptr.h"
 #include "base/memory/scoped_vector.h"
 #include "base/observer_list.h"
 #include "ui/display/types/chromeos/native_display_delegate.h"
 
 namespace ui {
 
+class DisplayEventListener;
 class DisplaySnapshotDri;
 class DriSurfaceFactory;
 
 class NativeDisplayDelegateDri : public NativeDisplayDelegate {
  public:
-  NativeDisplayDelegateDri(DriSurfaceFactory* surface_factory);
+  NativeDisplayDelegateDri(DriSurfaceFactory* surface_factory,
+                           scoped_ptr<DisplayEventListener> display_listener_);
   virtual ~NativeDisplayDelegateDri();
 
   // NativeDisplayDelegate overrides:
@@ -47,7 +50,11 @@ class NativeDisplayDelegateDri : public NativeDisplayDelegate {
   virtual void RemoveObserver(NativeDisplayObserver* observer) OVERRIDE;
 
  private:
+  // Callback for display events.
+  void OnDisplayEvent();
+
   DriSurfaceFactory* surface_factory_;  // Not owned.
+  scoped_ptr<DisplayEventListener> display_event_listener_;
   ScopedVector<const DisplayMode> cached_modes_;
   ScopedVector<DisplaySnapshotDri> cached_displays_;
   ObserverList<NativeDisplayObserver> observers_;