RFR: 8353685: Open some JComboBox bugs 4 [v3]

[Alisen Chung]

> Updating and opening some JComboBox bugs

Alisen Chung has updated the pull request incrementally with one additional commit since the last revision:

  add longer delay, remove headful from manual test, spacing

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Changes:
  - all: https://git.openjdk.org/jdk/pull/24733/files
  - new: https://git.openjdk.org/jdk/pull/24733/files/0799d454..911acf73

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24733&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24733&range=01-02

  Stats: 7 lines in 3 files changed: 4 ins; 1 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/24733.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24733/head:pull/24733

PR: https://git.openjdk.org/jdk/pull/24733