Added 1 liner to fix shelf background hiding on side shelf alignment.

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 7c3731a32cc7297f96d06b73470c0005b7041292..18b73738137725324ebe89f0fa55897835c48a4b 100644
--- a/ash/shelf/shelf_layout_manager.h
+++ b/ash/shelf/shelf_layout_manager.h
@@ -328,6 +328,9 @@ class ASH_EXPORT ShelfLayoutManager
   // False when neither the auto hide timer nor the timer task are running.
   bool mouse_over_shelf_when_auto_hide_timer_started_;
 
+  // Whether the fullscreen app list feature is enabled.
+  const bool is_fullscreen_app_list_enabled_;
+
   base::ObserverList<ShelfLayoutManagerObserver> observers_;
 
   // The shelf reacts to gesture-drags, and can be set to auto-hide for certain