RFR: 8196018: java/awt/Scrollbar/ScrollbarMouseWheelTest/ScrollbarMouseWheelTest.java fails [v2]

[Alexander Zvegintsev]

> The issue contains evaluation:
> * the test is not failing on Windows
> * it also fails on Linux(but provided stack trace with failure is from different test)
> 
> I rechecked the test and it does not fail on all platforms.
> 
> Test is stabilized:
> * replaced synchronization on windowActivated event with standard `robot.waitForIdle(); robot.delay(1000);`
> * Robot autoDelay decreased to 250 to make the test go faster. It it still a reasonable value.
> 
> CI testing looks good also.

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

  addressing review comments

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

Changes:
  - all: https://git.openjdk.org/jdk/pull/11213/files
  - new: https://git.openjdk.org/jdk/pull/11213/files/c2ada26e..1a75b89d

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=11213&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=11213&range=00-01

  Stats: 5 lines in 1 file changed: 3 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/11213.diff
  Fetch: git fetch https://git.openjdk.org/jdk pull/11213/head:pull/11213

PR: https://git.openjdk.org/jdk/pull/11213