[gtksourceview] hoverdisplay: give GtkSourceHoverDisplay a CSS name

[Christian Hergert <chergert src gnome org>]

commit 550b9a9836bbbc2f9c184682e97f0fc2357459bd
Author: Christian Hergert <chergert redhat com>
Date:   Tue Sep 6 13:56:03 2022 -0700

    hoverdisplay: give GtkSourceHoverDisplay a CSS name

 gtksourceview/gtksourcehoverdisplay.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/gtksourceview/gtksourcehoverdisplay.c b/gtksourceview/gtksourcehoverdisplay.c
index ebfad311..310de86b 100644
--- a/gtksourceview/gtksourcehoverdisplay.c
+++ b/gtksourceview/gtksourcehoverdisplay.c
@@ -64,6 +64,7 @@ gtk_source_hover_display_class_init (GtkSourceHoverDisplayClass *klass)
        object_class->dispose = gtk_source_hover_display_dispose;
 
        gtk_widget_class_set_layout_manager_type (widget_class, GTK_TYPE_BIN_LAYOUT);
+       gtk_widget_class_set_css_name (widget_class, "GtkSourceHoverDisplay");
 }
 
 static void