Center the search results as well

Use overlay_scrollbars and the same padding.

https://bugzilla.gnome.org/show_bug.cgi?id=694701

js/ui/searchDisplay.js

@@ -331,7 +331,8 @@ const SearchResults = new Lang.Class({
 
         this._scrollView = new St.ScrollView({ x_fill: true,
                                                y_fill: false,
-                                               style_class: 'vfade' });
+                                               overlay_scrollbars: true,
+                                               style_class: 'search-display vfade' });
         this._scrollView.set_policy(Gtk.PolicyType.NEVER, Gtk.PolicyType.AUTOMATIC);
         this._scrollView.add_actor(scrollChild);
         let action = new Clutter.PanAction({ interpolate: true });