[gnome-shell] popupMenu: Fix PopupSliderMenuItem

[Jasper St. Pierre <jstpierre src gnome org>]

commit e645edbda731950bf0fa48e26cb4a34d81b056e9
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Thu Jun 6 15:49:20 2013 -0400

    popupMenu: Fix PopupSliderMenuItem
    
    It seems a bad rebase took this away.

 js/ui/popupMenu.js |    4 +---
 1 files changed, 1 insertions(+), 3 deletions(-)
---
diff --git a/js/ui/popupMenu.js b/js/ui/popupMenu.js
index 207ffbb..3332fe9 100644
--- a/js/ui/popupMenu.js
+++ b/js/ui/popupMenu.js
@@ -518,9 +518,7 @@ const PopupSliderMenuItem = new Lang.Class({
         this._slider.connect('value-changed', Lang.bind(this, function(actor, value) {
             this.emit('value-changed', value);
         }));
-
-        this._releaseId = this._motionId = 0;
-        this._dragging = false;
+        this.addActor(this._slider.actor);
     },
 
     setValue: function(value) {