<Swing Dev> [13] RFR 8224876:javax/swing/JWindow/ShapedAndTranslucentWindows/ShapedPerPixelTranslucentGradient.java fails on linux-x64

[Prasanta Sadhukhan]

Hi All,

Please review a test-fix for an issue where the test check fails after 
the content of window is dragged & resized.
Test is passing in local ubuntu18.04 system but is failing on mach5 
linux headful system as test check for pixels happens too quickly after 
window drag/resize.
Increased delay between test drag&drop and check to make sure check 
happens after reasonable amount of time. Test now pass in all mach5 systems.

Bug: https://bugs.openjdk.java.net/browse/JDK-8224876
webrev: http://cr.openjdk.java.net/~psadhukhan/8224876/webrev.0/

Regards
Prasanta