ADDITIONAL SYSTEM INFORMATION :
Microsoft Windows [Version 10.0.16299.371]

HighSierra
Darwin unit 17.5.0 Darwin Kernel Version 17.5.0: Fri Apr 13 19:32:32 PDT 2018; root:xnu-4570.51.2~1/RELEASE_X86_64 x86_64

A DESCRIPTION OF THE PROBLEM :
The test java/awt/Focus/ClearLwQueueBreakTest/ClearLwQueueBreakTest.java fails on Windows, MacOS with the message "TestFailedException: Test failed: target component didn't get focus!"
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/java/awt/Focus/ClearLwQueueBreakTest/ClearLwQueueBreakTest.java

ACTUAL -
#section:main
----------messages:(5/209)----------
command: main ClearLwQueueBreakTest
reason: User specified action: run main ClearLwQueueBreakTest
Mode: othervm
Additional options from @modules: --add-modules java.desktop
elapsed time (seconds): 1.115
----------configuration:(3/43)----------
Boot Layer
  add modules: java.desktop

----------System.out:(2/58)----------
Any messages for the tester will display here.
Stage 1.
----------System.err:(15/1021)----------
TestFailedException: Test failed: target component didn't get focus!
at ClearLwQueueBreakTest.test1(ClearLwQueueBreakTest.java:153)
at ClearLwQueueBreakTest.start(ClearLwQueueBreakTest.java:133)
at ClearLwQueueBreakTest.main(ClearLwQueueBreakTest.java:58)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.base/java.lang.reflect.Method.invoke(Method.java:564)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
at java.base/java.lang.Thread.run(Thread.java:844)

JavaTest Message: Test threw exception: TestFailedException: Test failed: target component didn't get focus!
JavaTest Message: shutting down test

STATUS:Failed.`main' threw exception: TestFailedException: Test failed: target component didn't get focus!

---------- BEGIN SOURCE ----------
http://hg.openjdk.java.net/jdk10/jdk10/jdk/file/777356696811/test/java/awt/Focus/ClearLwQueueBreakTest/ClearLwQueueBreakTest.java
---------- END SOURCE ----------

FREQUENCY : always