RFR: 8282936: Write a regression test for JDK-4615365 [v2]

[Manukumar V S]

> Write a regression test for [JDK-4615365](https://bugs.openjdk.java.net/browse/JDK-4615365) : JSplitPane current and last divider positions incorrect when realized
> 
> Issue:
> JSplitPane component with a left and right component has its current divider
> position incorrectly set to -1 once it is fully realized. For JDK 1.3.1, its
> value is set to 0. The current position of the divider should be the current
> position of the divider once layout management is complete. If the divider is
> moved one pixel, the current divider position is updated to the correct value
> but the last divider position is then set to -1 (i.e. the last value of the
> current divider position). If the divider is moved again, everything is OK.
> 
> Testing:
> Java 1.4.0 -> Test Failed.
> $ j2sdk1.4.0/bin/java bug4615365
> current= -1, last= 0
> Test Failed.
> 
> Java 1.4.1 -> Test Passed.
> $ j2sdk1.4.1/bin/java bug4615365
> current= 97, last= -1
> Test Passed.

Manukumar V S has updated the pull request incrementally with two additional commits since the last revision:

 - Removed extra blank line before import static
 - Review comment fixed: Limited 80 chars per line

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

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/7802/files
  - new: https://git.openjdk.java.net/jdk/pull/7802/files/3ae1e194..9e810adf

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=7802&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=7802&range=00-01

  Stats: 31 lines in 1 file changed: 17 ins; 0 del; 14 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7802.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7802/head:pull/7802

PR: https://git.openjdk.java.net/jdk/pull/7802