Both javax/swing/JComboBox/8033069/bug8033069NoScrollBar.java and javax/swing/JComboBox/8033069/bug8033069ScrollBar.java tests fail on Linux in CI.

---------System.out:(5/198)----------
Look and Feel: javax.swing.plaf.metal.MetalLookAndFeel
Test passed
Look and Feel: javax.swing.plaf.nimbus.NimbusLookAndFeel
Test passed
Look and Feel: com.sun.java.swing.plaf.motif.MotifLookAndFeel
----------System.err:(17/1036)----------
java.lang.RuntimeException: cb1 popup is not visible
        at bug8033069NoScrollBar.assertEquals(bug8033069NoScrollBar.java:181)
        at bug8033069NoScrollBar.assertTrue(bug8033069NoScrollBar.java:172)
        at bug8033069NoScrollBar.runTest(bug8033069NoScrollBar.java:121)
        at bug8033069NoScrollBar.iterateLookAndFeels(bug8033069NoScrollBar.java:74)
        at bug8033069NoScrollBar.main(bug8033069NoScrollBar.java:65)
        at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
        at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
        at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
        at java.lang.reflect.Method.invoke(Method.java:498)
        at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:127)
        at java.lang.Thread.run(Thread.java:750)

JavaTest Message: Test threw exception: java.lang.RuntimeException: cb1 popup is not visible
JavaTest Message: shutting down test

STATUS:Failed.`main' threw exception: java.lang.RuntimeException: cb1 popup is not visible


The log for the bug8033069ScrollBar.java test looks the same.