[gnome-shell/gnome-3-6] screenShield: explicitly load gnome-screensaver in fallback mode.

[Ray Strode <halfline src gnome org>]

commit 4e58026e101eede05cc7c6c0ef11d73b6a348805
Author: Tim Lunn <tim feathertop org>
Date:   Fri Oct 19 10:44:28 2012 +1100

    screenShield: explicitly load gnome-screensaver in fallback mode.
    
    When running gnome-shell from lightDM, gnome-screensaver is no
    longer auto-loaded. As a result the dbus calls for Lock user etc
    will fail.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=683060
    Bug-Ubuntu: https://launchpad.net/bugs/1064354

 js/ui/screenShield.js |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js
index 07e450f..2069568 100644
--- a/js/ui/screenShield.js
+++ b/js/ui/screenShield.js
@@ -21,6 +21,7 @@ const Overview = imports.ui.overview;
 const MessageTray = imports.ui.messageTray;
 const ShellDBus = imports.ui.shellDBus;
 const Tweener = imports.ui.tweener;
+const Util = imports.misc.util;
 
 const SCREENSAVER_SCHEMA = 'org.gnome.desktop.screensaver';
 const LOCK_ENABLED_KEY = 'lock-enabled';
@@ -865,6 +866,8 @@ const ScreenShieldFallback = new Lang.Class({
     Name: 'ScreenShieldFallback',
 
     _init: function() {
+        Util.spawn(['gnome-screensaver']);
+
         this._proxy = new Gio.DBusProxy({ g_connection: Gio.DBus.session,
                                           g_name: 'org.gnome.ScreenSaver',
                                           g_object_path: '/org/gnome/ScreenSaver',