cleanup: Port non-GObject classes to JS6 classes

ES6 finally adds standard class syntax to the language, so we can
replace our custom Lang.Class framework with the new syntax. Any
classes that inherit from GObject will need special treatment,
so limit the port to regular javascript classes for now.

https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/361

js/ui/endSessionDialog.js

@@ -16,7 +16,6 @@
  * along with this program; if not, see <http://www.gnu.org/licenses/>.
  */
 
-const Lang = imports.lang;
 const Mainloop = imports.mainloop;
 
 const AccountsService = imports.gi.AccountsService;
@@ -235,13 +234,10 @@ function init() {
     _endSessionDialog = new EndSessionDialog();
 }
 
-var EndSessionDialog = new Lang.Class({
-    Name: 'EndSessionDialog',
-    Extends: ModalDialog.ModalDialog,
-
-    _init() {
-        this.parent({ styleClass: 'end-session-dialog',
-                      destroyOnClose: false });
+var EndSessionDialog = class EndSessionDialog extends ModalDialog.ModalDialog {
+    constructor() {
+        super({ styleClass: 'end-session-dialog',
+                destroyOnClose: false });
 
         this._loginManager = LoginManager.getLoginManager();
         this._userManager = AccountsService.UserManager.get_default();
@@ -356,12 +352,12 @@ var EndSessionDialog = new Lang.Class({
 
         this._dbusImpl = Gio.DBusExportedObject.wrapJSObject(EndSessionDialogIface, this);
         this._dbusImpl.export(Gio.DBus.session, '/org/gnome/SessionManager/EndSessionDialog');
-    },
+    }
 
     _onDestroy() {
         this._user.disconnect(this._userLoadedId);
         this._user.disconnect(this._userChangedId);
-    },
+    }
 
     _sync() {
         let open = (this.state == ModalDialog.State.OPENING || this.state == ModalDialog.State.OPENED);
@@ -434,7 +430,7 @@ var EndSessionDialog = new Lang.Class({
         this._scrollView.visible = hasApplications || hasSessions;
         this._applicationHeader.visible = hasApplications;
         this._sessionHeader.visible = hasSessions;
-    },
+    }
 
     _updateButtons() {
         let dialogContent = DialogContent[this._type];
@@ -456,20 +452,20 @@ var EndSessionDialog = new Lang.Class({
         }
 
         this.setButtons(buttons);
-    },
+    }
 
     close(skipSignal) {
-        this.parent();
+        super.close();
 
         if (!skipSignal)
             this._dbusImpl.emit_signal('Closed', null);
-    },
+    }
 
     cancel() {
         this._stopTimer();
         this._dbusImpl.emit_signal('Canceled', null);
         this.close();
-    },
+    }
 
     _confirm(signal) {
         let callback = () => {
@@ -504,11 +500,11 @@ var EndSessionDialog = new Lang.Class({
         } else {
             this._triggerOfflineUpdateCancel(callback);
         }
-    },
+    }
 
     _onOpened() {
         this._sync();
-    },
+    }
 
     _triggerOfflineUpdateReboot(callback) {
         this._pkOfflineProxy.TriggerRemote('reboot', (result, error) => {
@@ -517,7 +513,7 @@ var EndSessionDialog = new Lang.Class({
 
             callback();
         });
-    },
+    }
 
     _triggerOfflineUpdateShutdown(callback) {
         this._pkOfflineProxy.TriggerRemote('power-off', (result, error) => {
@@ -526,7 +522,7 @@ var EndSessionDialog = new Lang.Class({
 
             callback();
         });
-    },
+    }
 
     _triggerOfflineUpdateCancel(callback) {
         this._pkOfflineProxy.CancelRemote((result, error) => {
@@ -535,7 +531,7 @@ var EndSessionDialog = new Lang.Class({
 
             callback();
         });
-    },
+    }
 
     _startTimer() {
         let startTime = GLib.get_monotonic_time();
@@ -559,7 +555,7 @@ var EndSessionDialog = new Lang.Class({
             return GLib.SOURCE_REMOVE;
         });
         GLib.Source.set_name_by_id(this._timerId, '[gnome-shell] this._confirm');
-    },
+    }
 
     _stopTimer() {
         if (this._timerId > 0) {
@@ -568,7 +564,7 @@ var EndSessionDialog = new Lang.Class({
         }
 
         this._secondsLeft = 0;
-    },
+    }
 
     _constructListItemForApp(inhibitor, app) {
         let actor = new St.BoxLayout({ style_class: 'end-session-dialog-app-list-item',
@@ -593,7 +589,7 @@ var EndSessionDialog = new Lang.Class({
         }
 
         return actor;
-    },
+    }
 
     _onInhibitorLoaded(inhibitor) {
         if (this._applications.indexOf(inhibitor) < 0) {
@@ -612,7 +608,7 @@ var EndSessionDialog = new Lang.Class({
         }
 
         this._sync();
-    },
+    }
 
     _constructListItemForSession(session) {
         let avatar = new UserWidget.Avatar(session.user, { iconSize: _ITEM_ICON_SIZE });
@@ -642,7 +638,7 @@ var EndSessionDialog = new Lang.Class({
         actor.label_actor = nameLabel;
 
         return actor;
-    },
+    }
 
     _loadSessions() {
         this._loginManager.listSessions(result => {
@@ -684,7 +680,7 @@ var EndSessionDialog = new Lang.Class({
 
             this._sync();
         });
-    },
+    }
 
     OpenAsync(parameters, invocation) {
         let [type, timestamp, totalSecondsToStayOpen, inhibitorObjectPaths] = parameters;
@@ -754,9 +750,9 @@ var EndSessionDialog = new Lang.Class({
             invocation.return_value(null);
             this.disconnect(signalId);
         });
-    },
+    }
 
     Close(parameters, invocation) {
         this.close();
     }
-});
+};