RFR: 8315317: Add test for JDK-8262518 [v2]

[Andy Goryachev]

On Mon, 4 Sep 2023 06:34:18 GMT, Prasanta Sadhukhan <psadhukhan at openjdk.org> wrote:

>> Added automated test for 8262518:SwingNode.setContent does not close previous content, resulting in memory leak
>
> Prasanta Sadhukhan has updated the pull request incrementally with one additional commit since the last revision:
> 
>   Better failure detection

looking good 🕶
even with Thread.sleep(1);

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Marked as reviewed by angorya (Reviewer).

PR Review: https://git.openjdk.org/jfx/pull/1228#pullrequestreview-1617654536