RFR: 8206430: Use consistent pattern for startup in FX system tests [v6]

[Kevin Rushforth]

On Wed, 16 Nov 2022 20:12:26 GMT, Andy Goryachev <angorya at openjdk.org> wrote:

>> 1. Introduced the following utility methods:
>> - Util.launch
>> - Util.shutdown
>> - Util.waitForLatch
>> 2. Fixed the out-of order calls to Stage.hide() and Platform.exit() in many tests' shutdowns.
>> 3. Replaced local waitForLatch copies with Util.waitForLatch
>
> Andy Goryachev has updated the pull request incrementally with one additional commit since the last revision:
> 
>   8206430: review comments

Looks good. Tested on all three platforms. I left a minor doc comment (which I don't suggest you do anything about, since we don't generate docs for tests), as a note for future reference.

tests/system/src/test/java/test/util/Util.java line 313:

> 311:      * @param startupLatch - a latch used to communicate successful start of the application
> 312:      * @param applicationClass - application to launch
> 313:      * @param args - command line arguments

Since we don't generate javadocs for our tests, this doesn't matter, but for future refence, there should not be any punctuation (i.e., no `-`) after the name of the parameter.

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Marked as reviewed by kcr (Lead).

PR: https://git.openjdk.org/jfx/pull/950