RFR: 8233648: [TESTBUG] DefaultMenuBarTest.java failing on macos [v2]

[Alexander Zvegintsev]

> Looks like this test does not fail anymore.
> 
> It does not fail once even without changes, but I've added extra `waitForIdle()` just for safety.
> 
> Checked on ~350 test runs.

Alexander Zvegintsev has updated the pull request incrementally with two additional commits since the last revision:

 - remove wildcard imports
 - cleanup

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/6015/files
  - new: https://git.openjdk.java.net/jdk/pull/6015/files/5218b7b7..e1c0625e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=6015&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=6015&range=00-01

  Stats: 24 lines in 1 file changed: 5 ins; 12 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/6015.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/6015/head:pull/6015

PR: https://git.openjdk.java.net/jdk/pull/6015