RFR: 8316627: JViewport Test headless failure [v2]

[Damon Nguyen]

> Converted test needs headful tag added to avoid failures.

Damon Nguyen has updated the pull request incrementally with one additional commit since the last revision:

  Remove invokeAndWait and sleep entirely

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Changes:
  - all: https://git.openjdk.org/jdk/pull/15847/files
  - new: https://git.openjdk.org/jdk/pull/15847/files/01358e68..d36d6a13

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15847&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15847&range=00-01

  Stats: 26 lines in 1 file changed: 0 ins; 13 del; 13 mod
  Patch: https://git.openjdk.org/jdk/pull/15847.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15847/head:pull/15847

PR: https://git.openjdk.org/jdk/pull/15847