RFR: JDK-8282777: Create a Regression test for JDK-4515031 [v3]

[Srinivas Mandalika]

> Create a Regression test for [JDK-4515031](https://bugs.openjdk.java.net/browse/JDK-4515031)
> 
> The issue indicates the need for a a getAccessibleDescription being implemented for the JFileChooser.
> The test added verifies the same.
> This review is for migrating tests from a closed test suite to open.

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

  Review Comments Fixed: Button on EDT, split long lines, volatile description string

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7738/files
  - new: https://git.openjdk.java.net/jdk/pull/7738/files/c239c2c9..76db0fa6

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7738&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7738&range=01-02

  Stats: 29 lines in 1 file changed: 15 ins; 7 del; 7 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7738.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7738/head:pull/7738

PR: https://git.openjdk.java.net/jdk/pull/7738