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/runDialog.js

@@ -3,7 +3,6 @@
 const Clutter = imports.gi.Clutter;
 const Gio = imports.gi.Gio;
 const GLib = imports.gi.GLib;
-const Lang = imports.lang;
 const Meta = imports.gi.Meta;
 const St = imports.gi.St;
 const Shell = imports.gi.Shell;
@@ -30,13 +29,10 @@ const EXEC_ARG_KEY = 'exec-arg';
 
 var DIALOG_GROW_TIME = 0.1;
 
-var RunDialog = new Lang.Class({
-    Name: 'RunDialog',
-    Extends: ModalDialog.ModalDialog,
-
-    _init() {
-        this.parent({ styleClass: 'run-dialog',
-                      destroyOnClose: false });
+var RunDialog = class extends ModalDialog.ModalDialog {
+    constructor() {
+        super({ styleClass: 'run-dialog',
+                destroyOnClose: false });
 
         this._lockdownSettings = new Gio.Settings({ schema_id: LOCKDOWN_SCHEMA });
         this._terminalSettings = new Gio.Settings({ schema_id: TERMINAL_SCHEMA });
@@ -144,7 +140,7 @@ var RunDialog = new Lang.Class({
             }
             return Clutter.EVENT_PROPAGATE;
         });
-    },
+    }
 
     _getCommandCompletion(text) {
         function _getCommon(s1, s2) {
@@ -189,7 +185,7 @@ var RunDialog = new Lang.Class({
 
         let common = results.reduce(_getCommon, null);
         return common.substr(text.length);
-    },
+    }
 
     _getCompletion(text) {
         if (text.indexOf('/') != -1) {
@@ -197,7 +193,7 @@ var RunDialog = new Lang.Class({
         } else {
             return this._getCommandCompletion(text);
         }
-    },
+    }
 
     _run(input, inTerminal) {
         let command = input;
@@ -248,7 +244,7 @@ var RunDialog = new Lang.Class({
                 }
             }
         }
-    },
+    }
 
     _showError(message) {
         this._commandError = true;
@@ -269,7 +265,7 @@ var RunDialog = new Lang.Class({
                                }
                              });
         }
-    },
+    }
 
     _restart() {
         if (Meta.is_wayland_compositor()) {
@@ -279,7 +275,7 @@ var RunDialog = new Lang.Class({
         this._shouldFadeOut = false;
         this.close();
         Meta.restart(_("Restarting…"));
-    },
+    }
 
     open() {
         this._history.lastItem();
@@ -290,7 +286,7 @@ var RunDialog = new Lang.Class({
         if (this._lockdownSettings.get_boolean(DISABLE_COMMAND_LINE_KEY))
             return;
 
-        this.parent();
-    },
-});
+        super.open();
+    }
+};
 Signals.addSignalMethods(RunDialog.prototype);