[8u20] backport request for 8019180: Use JComboBox as it's own ActionListener leads to unexpected behaviour

[sergey malenkov]

Hello,

This is a direct backport from jdk 9 to jdk 8u.

Issue: http://bugs.openjdk.java.net/browse/JDK-8019180
Webrev: http://cr.openjdk.java.net/~malenkov/8019180.9.0/
Changeset: http://hg.openjdk.java.net/jdk9/client/jdk/rev/e86678f580ae
Reviewers: Alexandr Scherbatiy, Sergey Bylokhov

Thanks,
SAM