java/awt/grab/GrabOnUnfocusableToplevel/GrabOnUnfocusableToplevel.java fails repeatably on Ubuntu 17.10


----------System.err:(13/820)----------
java.lang.RuntimeException: menu was not shown
at GrabOnUnfocusableToplevel.main(GrabOnUnfocusableToplevel.java:79)
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:569)
at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:115)
at java.base/java.lang.Thread.run(Thread.java:832)

JavaTest Message: Test threw exception: java.lang.RuntimeException: menu was not shown
JavaTest Message: shutting down test