RFR: 8148041: Test java/awt/Mouse/TitleBarDoubleClick/TitleBarDoubleClick fails on Ubuntu with mouseReleased event after double click on title bar [v2]

[Alexander Zvegintsev]

> This test was problem listed with ["some tests that leave windows open on the desktop" reason](https://github.com/openjdk/jdk/commit/fd8df3adf13f5df8f5f95482b8e0a70bc519f39f)
> 
> The main issue with the test is that it may pass, but in fact the actual test was not even performed. <br>`jtreg` kills the test window after exiting main and ends the test before it double clicks on window's title(actual test starts from `windowActivated` event).
> 
> So the test was refactored and stabilized:
> * robot invocation moved from EDT to main thread.
> * throwing test exception is performed only after frame is disposed
> * extra delay added after showing window.
> 
> Old Ubuntu 16.04 and macOS 10.10.5 failures is no longer reproducible on modern systems.
> 
> CI testing looks good.

Alexander Zvegintsev has updated the pull request incrementally with one additional commit since the last revision:

  clean up

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11150/files
  - new: https://git.openjdk.org/jdk/pull/11150/files/59642367..17e07e37

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11150&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11150&range=00-01

  Stats: 25 lines in 1 file changed: 9 ins; 0 del; 16 mod
  Patch: https://git.openjdk.org/jdk/pull/11150.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11150/head:pull/11150

PR: https://git.openjdk.org/jdk/pull/11150