Convert //ash from scoped_ptr to std::unique_ptr

ash/shelf/shelf_layout_manager.h

Index: ash/shelf/shelf_layout_manager.h
diff --git a/ash/shelf/shelf_layout_manager.h b/ash/shelf/shelf_layout_manager.h
index bfeda23c25bd4ad5703bc1d3a018ba36be79e6e2..326ea1e44ee4b04b9dabe20ae7fd67417552a1cd 100644
--- a/ash/shelf/shelf_layout_manager.h
+++ b/ash/shelf/shelf_layout_manager.h
@@ -354,10 +354,10 @@ class ASH_EXPORT ShelfLayoutManager
 
   // EventFilter used to detect when user moves the mouse over the shelf to
   // trigger showing the shelf.
-  scoped_ptr<AutoHideEventFilter> auto_hide_event_filter_;
+  std::unique_ptr<AutoHideEventFilter> auto_hide_event_filter_;
 
   // EventFilter used to detect when user issues a gesture on a bezel sensor.
-  scoped_ptr<ShelfBezelEventFilter> bezel_event_filter_;
+  std::unique_ptr<ShelfBezelEventFilter> bezel_event_filter_;
 
   base::ObserverList<ShelfLayoutManagerObserver> observers_;