javax/swing/JPopupMenu/4634626/bug4634626.java fails on Windows&MacOS

A DESCRIPTION OF THE PROBLEM :
The test javax/swing/JPopupMenu/4634626/bug4634626.java fails on Windows and MacOS. The issue was not observed on Linux.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
$ jtreg -testjdk:/cygdrive/c/Program\ Files/Java/jdk-10.0.1 -javaoptions:"-Djava.awt.headless=false" -timeoutFactor:2 test/javax/swing/JPopupMenu/4634626/bug4634626.java

ACTUAL -
#section:applet
----------messages:(4/186)----------
command: applet bug4634626.html
reason: User specified action: run applet bug4634626.html
Additional options from @modules: --add-modules java.desktop
elapsed time (seconds): 9.442
----------System.out:(0/0)----------
----------System.err:(5/315)----------
java.lang.RuntimeException: Test failed
at bug4634626.init(bug4634626.java:126)
at com.sun.javatest.regtest.agent.AppletWrapper$AppletRunnable.run(AppletWrapper.java:155)
at java.base/java.lang.Thread.run(Thread.java:844)
STATUS:Failed.Applet thread threw exception: java.lang.RuntimeException: Test failed

---------- BEGIN SOURCE ----------
http://hg.openjdk.java.net/jdk10/jdk10/jdk/file/777356696811/test/javax/swing/JPopupMenu/4634626
---------- END SOURCE ----------

FREQUENCY : always