[8u40] RFR: RT-39764: [macosx] Media crashes when changing EQ band center frequency

[David DeHaven]

Kevin, Kirill, please review my fix for RT-39764.

JIRA:
https://javafx-jira.kenai.com/browse/RT-39764

Webrev:
http://cr.openjdk.java.net/~ddehaven/RT-39764/rt.0/index.html

-DrD-