<AWT Dev> [9] Review Request: JDK-8047799 Remove WindowClosingSupport

[Petr Pchelko]

Hello, AWT Team.

Please review a weekly-cleanup fix for the issue:
https://bugs.openjdk.java.net/browse/JDK-8047799
The fix is available at:
http://cr.openjdk.java.net/~pchelko/9/8047799/webrev/

This feature was added for plugin in 1.4. I've grepped the sources and the interfaces and methods are not used any more.
I've run modality JTREG and checked the test for an original bug, everything seems to work fine. JPRT build succeeds.

With best regards. Petr.