RFR: 8342508: Use latch in BasicMenuUI/bug4983388.java instead of delay

[Sergey Bylokhov]

On Fri, 18 Oct 2024 15:12:06 GMT, Alexey Ivanov <aivanov at openjdk.org> wrote:

> Use a `CountDownLatch` in `javax/swing/plaf/basic/BasicMenuUI/4983388/bug4983388.java` instead of delay.
> 
> The latch provides a direct way to synchronise EDT and main thread, the test will finish quicker.
> 
> I ran the updated test a few times with `JTREG=REPEAT_COUNT=20`, the test always passed in the CI.

Marked as reviewed by serb (Reviewer).

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PR Review: https://git.openjdk.org/jdk/pull/21585#pullrequestreview-2378538772