[gnome-shell] screenShield: Chain up Arrow's style_changed vfunc

[Rui Matos <rtcm src gnome org>]

commit b5dd4d1456f4305f08ecbafc30b992a4c0269a92
Author: Rui Matos <tiagomatos gmail com>
Date:   Tue Jun 14 17:55:35 2016 +0200

    screenShield: Chain up Arrow's style_changed vfunc
    
    This makes style changes propagate to our child widget as they
    should.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=739178

 js/ui/screenShield.js |    2 ++
 1 files changed, 2 insertions(+), 0 deletions(-)
---
diff --git a/js/ui/screenShield.js b/js/ui/screenShield.js
index e4ffde5..c6202fe 100644
--- a/js/ui/screenShield.js
+++ b/js/ui/screenShield.js
@@ -399,6 +399,8 @@ const Arrow = new Lang.Class({
             this._shadowHelper = St.ShadowHelper.new(this._shadow);
         else
             this._shadowHelper = null;
+
+        this.parent();
     },
 
     vfunc_paint: function() {