RFR: 8246202: ChoiceBoxSkin: misbehavior on switching skin, part 2 [v2]

[Jeanette Winzenburg]

> issue is a listener in ChoiceBoxSkin that wasn't removed (forgotten in my first cleanup ;)
> 
> Removed, un-ignored test that failed/passed before/after the fix

Jeanette Winzenburg has updated the pull request incrementally with one additional commit since the last revision:

  removed outdated fixme

-------------

Changes:
  - all: https://git.openjdk.java.net/jfx/pull/320/files
  - new: https://git.openjdk.java.net/jfx/pull/320/files/72f6e1a6..06c194d3

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jfx&pr=320&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jfx&pr=320&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 1 del; 0 mod
  Patch: https://git.openjdk.java.net/jfx/pull/320.diff
  Fetch: git fetch https://git.openjdk.java.net/jfx pull/320/head:pull/320

PR: https://git.openjdk.java.net/jfx/pull/320