hg: openjfx/2.2/controls/rt: fix RT-20720 NPE when removing last item in series in AreaChart

[hang.vo at oracle.com]

Changeset: 4889b4deb45e
Author:    Paru Somashekar <paru.somashekar at oracle.com>
Date:      2012-04-02 15:39 -0700
URL:       http://hg.openjdk.java.net/openjfx/2.2/controls/rt/rev/4889b4deb45e

fix RT-20720 NPE when removing last item in series in AreaChart

! javafx-ui-charts/src/javafx/scene/chart/AreaChart.java