RFR: 8282857: Create a regression test for JDK-4702690 [v3]

[Srinivas Mandalika]

> Create a regression test for [JDK-4702690](https://bugs.openjdk.java.net/browse/JDK-4702690)
> 
> In many cases in Swing it is possible to easily programatically determine that a JScrollBar (or two) is scrolling some JPanel (the cannonical case is a JScrollPane).
> In these cases, when accessibility support is instantiated (e.g. the AccessibleJScrollBar is created), a Controller_For and Controled_By relation should be instantiated between the AccessibleJScrollBar and the AccessibleJPanel that the JScrollBar and JPanel are associated with.
> 
> This allows various assistive technologies, especially voice-recognition technologies, to better interact with scrolling items.
> 
> The test put up validates that the target object for these properties(CONTROLLED_BY, CONTROLLED_FOR) are set appropriately for JScrollPane and JScrollBar.
> This review is for migrating tests from a closed test suite to open.

Srinivas Mandalika has updated the pull request incrementally with two additional commits since the last revision:

 - Review Comments Fixed: Swing Components on EDT, 80 chars lines
 - Review Comments Fixed: Swing Components on EDT, 80 chars lines

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Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7753/files
  - new: https://git.openjdk.java.net/jdk/pull/7753/files/f712f33f..01f8c430

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7753&range=02
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7753&range=01-02

  Stats: 30 lines in 1 file changed: 12 ins; 1 del; 17 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7753.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7753/head:pull/7753

PR: https://git.openjdk.java.net/jdk/pull/7753