hg: openjfx/2.1/master/rt: fixed RT-18931 ChoiceBox NPE when StageStyle has been changed twice

[hang.vo at oracle.com]

Changeset: 05002e14187b
Author:    psomashe
Date:      2012-01-17 17:59 -0800
URL:       http://hg.openjdk.java.net/openjfx/2.1/master/rt/rev/05002e14187b

fixed RT-18931 ChoiceBox NPE when StageStyle has been changed twice

! javafx-ui-controls/src/com/sun/javafx/scene/control/skin/ContextMenuContent.java