RFR: JDK-8283087: Create a test or JDK-4715503 [v2]

[Srinivas Mandalika]

> Create a test or [JDK-4715503](https://bugs.openjdk.java.net/browse/JDK-4715503)
> 
> The getAccessibleContext method for JTable column header cells returns an
>  AccessibleContext which cannot get the Bounding Rectangle for table header cells. The Bug causes problems with screen reader review mode.
> 
> The test added verifies that the are not exceptions and Bounding rectangles are returned for the Accessible Table Header Cells.
> 
> 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: null check added for Bounding Rectangles Returned.

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7807/files
  - new: https://git.openjdk.java.net/jdk/pull/7807/files/e8c21db0..2976ae1d

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7807&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7807&range=00-01

  Stats: 11 lines in 1 file changed: 8 ins; 0 del; 3 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7807.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7807/head:pull/7807

PR: https://git.openjdk.java.net/jdk/pull/7807