GrabHelper: always navigate focus when grabbing

Users of GrabHelper.grab() espect that the actor parameter (or one of its
children) will receive focus, irrespective of the previous focus location.
This fixes the key focus on the chat entry when expanding the notification.

https://bugzilla.gnome.org/show_bug.cgi?id=683449

js/ui/grabHelper.js

@@ -170,7 +170,7 @@ const GrabHelper = new Lang.Class({
         if (params.grabFocus)
             this._grabFocusCount++;
 
-        if (hadFocus)
+        if (hadFocus || params.grabFocus)
             _navigateActor(newFocus);
 
         return true;