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. ------------- Commit messages: - refactor - clean up Changes: https://git.openjdk.org/jdk/pull/11150/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11150&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8148041 Stats: 71 lines in 2 files changed: 19 ins; 8 del; 44 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
