[9] Review request for 8131066: JavaFX MediaPlayer crashes on dispose with certain MP4s

[Alexander Matveev]

Hi David,

Please review the fix:
https://bugs.openjdk.java.net/browse/JDK-8131066
http://cr.openjdk.java.net/~almatvee/8131066/webrev.00/

Crash happens, because AVPlayer was trying to notify AVFMediaPlayer 
about frame change after AVFMediaPlayer was released. Fixed by 
unregistering notification callback before AVFMediaPlayer is released.

Thanks,
Alexander