[macos]Dataflavor changes should be notified to FlavorListener

Dataflavor changes should be notified to FlavorListener
http://aurora-ds.us.oracle.com:9500/runs/317252.ute.st2-5/results/ResultDir/bug4259272/Report_bug4259272.html

Regression: NO
Reproducible in all updates of jdk 7, e g 7u21
(http://aurora.ru.oracle.com/functional/faces/RunDetails.xhtml?names=171960.ute.st2-5#testlist.DnD_Auto_All%20%5B!manual%5D%20(tonga)_AWT_DnD/Clipboard/Automated/ClipboardContentChangeTest/bug4259272)


Affected tests:
RULE AWT_DnD/Clipboard/Automated/ClipboardContentChangeTest/bug4259272 ExitCode 1