RFR: 8273485: Deadlock when also using Swing and exiting Fullscreen on Mac

[Florian Kirmaier]

When using Swing it's possible to generate a Deadlock.
 It's related to the nested eventloop started in enterFullScreenExitingLoop - and the RenderLock aquired when using setView in Scene.
 Sample Programm and Threaddump are added to the ticket.

Removing the nested loop fixes the Problem. 
I hope this doesn't have any side effect - so far i don't know of any.

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Commit messages:
 - JDK-8273485

Changes: https://git.openjdk.java.net/jfx/pull/622/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jfx&pr=622&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8273485
  Stats: 2 lines in 1 file changed: 0 ins; 2 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/622.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/622/head:pull/622

PR: https://git.openjdk.java.net/jfx/pull/622