[metacity/wip/muktupavels/issue-23] style-info: add .metacity style class to window

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 5abcb105c6c1c93efd386d0db2d5c9eb537bfdb6
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Mon Sep 6 21:43:12 2021 +0300

    style-info: add .metacity style class to window
    
    https://gitlab.gnome.org/GNOME/metacity/-/issues/23

 libmetacity/meta-style-info.c | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/libmetacity/meta-style-info.c b/libmetacity/meta-style-info.c
index 87d4cf29..23c9dca8 100644
--- a/libmetacity/meta-style-info.c
+++ b/libmetacity/meta-style-info.c
@@ -165,6 +165,7 @@ meta_style_info_constructed (GObject *object)
                           "window",
                           GTK_STYLE_CLASS_BACKGROUND,
                           style_info->composited == TRUE ? "csd" : "solid-csd",
+                          "metacity",
                           NULL);
 
   style_info->styles[META_STYLE_ELEMENT_DECORATION] =