[gnome-shell] lookingGlass: Use symbolic icon for close button

[Florian Müllner <fmuellner src gnome org>]

commit d78b416e1ac96f2acd7d3b4cb994bd0e067130e7
Author: Marco Trevisan (Treviño) <mail 3v1n0 net>
Date:   Thu Feb 28 16:20:47 2019 +0100

    lookingGlass: Use symbolic icon for close button
    
    As per commit 4d2dce2c, the actual close button is generated using custom css
    and a symbolic icon.
    
    Apply the same change to lookingGlass too.
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/425

 js/ui/lookingGlass.js | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/js/ui/lookingGlass.js b/js/ui/lookingGlass.js
index 920a24347..958211df0 100644
--- a/js/ui/lookingGlass.js
+++ b/js/ui/lookingGlass.js
@@ -382,6 +382,7 @@ var ObjInspector = class ObjInspector {
         }
 
         button = new St.Button({ style_class: 'window-close' });
+        button.add_actor(new St.Icon({ icon_name: 'window-close-symbolic' }));
         button.connect('clicked', this.close.bind(this));
         hbox.add(button);
         if (typeof(obj) == typeof({})) {