RFR: 8139208: [macosx] Issue with setExtendedState of JFrame [v3]

[Alisen Chung]

> Swapped order of showing frame and managing extended frame state.

Alisen Chung has updated the pull request incrementally with two additional commits since the last revision:

 - test update
 - added test, updated comment

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/15236/files
  - new: https://git.openjdk.org/jdk/pull/15236/files/145ded20..5d488e2b

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=15236&range=02
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=15236&range=01-02

  Stats: 54 lines in 2 files changed: 53 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jdk/pull/15236.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/15236/head:pull/15236

PR: https://git.openjdk.org/jdk/pull/15236