review Remove deprecated GTK2 calls in JavaFX

[David Hill]

Kevin,

A small change, substituting the "approved" way of calling GTK. This helps in a small way moving to GTK3 support.

bug: https://bugs.openjdk.java.net/browse/JDK-8145837
webrev: http://cr.openjdk.java.net/~ddhill/8145837/

-- 
David Hill<David.Hill at Oracle.com>
Java Embedded Development

"A man's feet should be planted in his country, but his eyes should survey the world."
-- George Santayana (1863 - 1952)