[gnome-games] platform: Add get_system_dir () method

[Alexander Mikhaylenko <alexm src gnome org>]

commit b1b93553fe2c5765637cb8d581df654057a0bdca
Author: Adwait Rawat <adwait rawat gmail com>
Date:   Mon Jun 22 20:58:47 2020 +0900

    platform: Add get_system_dir () method

 src/core/platform.vala | 8 ++++++++
 1 file changed, 8 insertions(+)
---
diff --git a/src/core/platform.vala b/src/core/platform.vala
index 67bc3619..1a438de1 100644
--- a/src/core/platform.vala
+++ b/src/core/platform.vala
@@ -22,4 +22,12 @@ public interface Games.Platform : Object {
        public static int compare (Platform a, Platform b) {
                return a.get_name ().collate (b.get_name ());
        }
+
+       public string get_system_dir () {
+               var platforms_dir = Application.get_platforms_dir ();
+               var id = get_id ();
+
+               return @"$platforms_dir/$id/system";
+       }
+
 }