[jdk11u-dev] RFR: 8296083: javax/swing/JTree/6263446/bug6263446.java fails intermittently on a VM

[Amos Shi]

Backport of [JDK-8296083](https://bugs.openjdk.org/browse/JDK-8296083)

Unclean Backport:
- `test/jdk/ProblemList.txt`
  - The change to this file has been ignored, because the `bug6263446.java` line does not exist

Test Succeeded in local Dev Apple M1 Laptop

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Commit messages:
 - Backport dd9aa7272d04b49dd5cbf3ff9f9091c7d63d68ae

Changes: https://git.openjdk.org/jdk11u-dev/pull/2391/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk11u-dev&pr=2391&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8296083
  Stats: 25 lines in 1 file changed: 21 ins; 1 del; 3 mod
  Patch: https://git.openjdk.org/jdk11u-dev/pull/2391.diff
  Fetch: git fetch https://git.openjdk.org/jdk11u-dev.git pull/2391/head:pull/2391

PR: https://git.openjdk.org/jdk11u-dev/pull/2391