<Swing Dev> [12] RFR JDK-8203904:javax/swing/JSplitPane/4816114/bug4816114.java: The divider location is wrong

[Prasanta Sadhukhan]

Hi All,

Please review a fix for an test problem where it is seen that the test 
passes on windows 7 but fails on windows 10
citing the JSplitPane divider location is wrong.
This is because in windows 10, the frame border width/height is 
different compared to windows 7 so splitpane is moved accordingly in the 
frame.

Proposed fix is to undecorate the frame so that border is not considered 
and splitpane position is considered from top/left of the frame itself.
webrev: http://cr.openjdk.java.net/~psadhukhan/8203904/webrev.0/
Bug: https://bugs.openjdk.java.net/browse/JDK-8203904

Additionally, the test frame is also disposed which was not done earlier.
The test now passes in windows 7, windows 10, ubuntu 18, mac 10.13.

Regards
Prasanta