arc: Fix missing notification on extended desktop

ui/arc/notification/arc_custom_notification_view.cc

Index: ui/arc/notification/arc_custom_notification_view.cc
diff --git a/ui/arc/notification/arc_custom_notification_view.cc b/ui/arc/notification/arc_custom_notification_view.cc
index 3e927c583f21c0de73a9a74685faa97de0f7e96b..b1588fce5c6ee8e970e22a2e9238ae6c64e4694c 100644
--- a/ui/arc/notification/arc_custom_notification_view.cc
+++ b/ui/arc/notification/arc_custom_notification_view.cc
@@ -310,12 +310,14 @@ void ArcCustomNotificationView::ViewHierarchyChanged(
   if (!details.is_add) {
     // Resets slide helper when this view is removed from its parent.
     slide_helper_.reset();
-  }
 
-  // Bail if native_view() has attached to a different widget.
-  if (widget && native_view() &&
-      views::Widget::GetTopLevelWidgetForNativeView(native_view()) != widget) {
-    return;
+    // Bail if this view is no longer attached to a widget or native_view() has
+    // attached to a different widget.
+    if (!widget || (native_view() &&
+                    views::Widget::GetTopLevelWidgetForNativeView(
+                        native_view()) != widget)) {
+      return;
+    }
   }
 
   views::NativeViewHost::ViewHierarchyChanged(details);