RFR: 8286172: Create an automated test for JDK-4516019 [v3]

[Srinivas Mandalika]

> Create an automated test for [JDK-4516019](https://bugs.openjdk.java.net/browse/JDK-4516019)
> 
> Clicking on the increment/decrement buttons of the spinner does not install focus on the spinner or one of its focusable children.
> 
> The test validates the same.
> 
> This review is for migrating tests from a closed test suite to open.
> 
> Testing:
> The test ran successfully on Mach5 with multiple runs (30) on windows-x64, linux-x64 and macos-x64.

Srinivas Mandalika has updated the pull request incrementally with one additional commit since the last revision:

  Review comments fixed: replaced sleep with robot.waitForIdle

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/8546/files
  - new: https://git.openjdk.java.net/jdk/pull/8546/files/b4fef8cd..69264c7e

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=8546&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=8546&range=01-02

  Stats: 14 lines in 1 file changed: 9 ins; 3 del; 2 mod
  Patch: https://git.openjdk.java.net/jdk/pull/8546.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/8546/head:pull/8546

PR: https://git.openjdk.java.net/jdk/pull/8546