[gnome-shell] screenShield: Fix crash with the idle monitor

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

commit 4618e1140657af2ba528fc63b7137fb4592dfac8
Author: Jasper St. Pierre <jstpierre mecheye net>
Date:   Fri Feb 15 07:59:23 2013 -0500

    screenShield: Fix crash with the idle monitor

 js/ui/screenShield.js |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js
index e9301a9..0329381 100644
--- a/js/ui/screenShield.js
+++ b/js/ui/screenShield.js
@@ -771,7 +771,7 @@ const ScreenShield = new Lang.Class({
         if (this._activationTime == 0)
             this._activationTime = GLib.get_monotonic_time();
 
-        this._becameActiveId = this.idleMonitor.add_user_active_watch(this._onUserBecameActive);
+        this._becameActiveId = this.idleMonitor.add_user_active_watch(Lang.bind(this, 
this._onUserBecameActive));
 
         let shouldLock = this._settings.get_boolean(LOCK_ENABLED_KEY) && !this._isLocked;