[gnome-shell] extensions-app: Use AdwApplication

[Marge Bot <marge-bot src gnome org>]

commit 891978b4eb8e9cca8563b9ddd22bdbc1b24b9595
Author: Romain Vigier <romain romainvigier fr>
Date:   Mon Oct 4 15:18:51 2021 +0200

    extensions-app: Use AdwApplication
    
    Initialize libadwaita, which loads the libadwaita stylesheet
    and allow following the dark style preference of the system.
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1997>

 subprojects/extensions-app/data/ui/extension-row.ui     | 1 -
 subprojects/extensions-app/data/ui/extensions-window.ui | 1 -
 subprojects/extensions-app/js/main.js                   | 4 ++--
 3 files changed, 2 insertions(+), 4 deletions(-)
---
diff --git a/subprojects/extensions-app/data/ui/extension-row.ui 
b/subprojects/extensions-app/data/ui/extension-row.ui
index ec56fedc9e..f41d8fbb7e 100644
--- a/subprojects/extensions-app/data/ui/extension-row.ui
+++ b/subprojects/extensions-app/data/ui/extension-row.ui
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
-  <requires lib="gtk+" version="3.20"/>
   <template class="ExtensionRow" parent="GtkListBoxRow">
     <property name="activatable">False</property>
     <child>
diff --git a/subprojects/extensions-app/data/ui/extensions-window.ui 
b/subprojects/extensions-app/data/ui/extensions-window.ui
index f049bd7e36..faafa05092 100644
--- a/subprojects/extensions-app/data/ui/extensions-window.ui
+++ b/subprojects/extensions-app/data/ui/extensions-window.ui
@@ -1,6 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <interface>
-  <requires lib="gtk+" version="3.20"/>
   <menu id="primary-menu">
     <section>
       <item>
diff --git a/subprojects/extensions-app/js/main.js b/subprojects/extensions-app/js/main.js
index 48d382f3f6..cbdac693f2 100644
--- a/subprojects/extensions-app/js/main.js
+++ b/subprojects/extensions-app/js/main.js
@@ -4,7 +4,7 @@ imports.gi.versions.Gtk = '4.0';
 
 const Gettext = imports.gettext;
 const Package = imports.package;
-const { Gdk, GLib, Gio, GObject, Gtk, Shew } = imports.gi;
+const { Adw, Gdk, GLib, Gio, GObject, Gtk, Shew } = imports.gi;
 
 Package.initFormat();
 
@@ -38,7 +38,7 @@ function toggleState(action) {
 }
 
 var Application = GObject.registerClass(
-class Application extends Gtk.Application {
+class Application extends Adw.Application {
     _init() {
         GLib.set_prgname('gnome-extensions-app');
         super._init({ application_id: Package.name });