[gtk] widget: Don't leak css transform

[Timm Bäder <baedert src gnome org>]

commit 424e46849ab043bff3483c7b1947e6a1737fc916
Author: Timm Bäder <mail baedert org>
Date:   Sat Jun 13 20:40:40 2020 +0200

    widget: Don't leak css transform

 gtk/gtkwidget.c | 2 ++
 1 file changed, 2 insertions(+)
---
diff --git a/gtk/gtkwidget.c b/gtk/gtkwidget.c
index cee8bbb1cd..55127a2ed7 100644
--- a/gtk/gtkwidget.c
+++ b/gtk/gtkwidget.c
@@ -3913,6 +3913,8 @@ gtk_widget_allocate (GtkWidget    *widget,
       transform = gsk_transform_translate (transform, &GRAPHENE_POINT_INIT (adjusted.width / 2, 
adjusted.height / 2));
       transform = gsk_transform_transform (transform, css_transform);
       transform = gsk_transform_translate (transform, &GRAPHENE_POINT_INIT (- adjusted.width / 2, - 
adjusted.height / 2));
+
+      gsk_transform_unref (css_transform);
     }
 
   adjusted.x += border.left + padding.left;