FULL PRODUCT VERSION :
java version "1.8.0_51"
Java(TM) SE Runtime Environment (build 1.8.0_51-b16)
Java HotSpot(TM) Client VM (build 25.51-b03, mixed mode)

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows [Version 6.1.7601]

A DESCRIPTION OF THE PROBLEM :
The test java/awt/grab/GrabOnUnfocusableToplevel/GrabOnUnfocusableToplevel.java fails on Windows because of RuntimeException: menu was not shown.
The issues was not observed on Linux, OSX


ERROR MESSAGES/STACK TRACES THAT OCCUR :
#section:main
----------messages:(4/155)----------
command: main GrabOnUnfocusableToplevel
reason: User specified action: run main GrabOnUnfocusableToplevel
Mode: othervm
elapsed time (seconds): 0.404
----------configuration:(0/0)----------
----------System.out:(0/0)----------
----------System.err:(13/756)----------
java.lang.RuntimeException: menu was not shown
        at GrabOnUnfocusableToplevel.main(GrabOnUnfocusableToplevel.java:78)
        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:497)
        at com.sun.javatest.regtest.agent.MainWrapper$MainThread.run(MainWrapper.java:110)
        at java.lang.Thread.run(Thread.java:745)

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

STATUS:Failed.`main' threw exception: java.lang.RuntimeException: menu was not shown

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
The test is from Regression (jtreg) tests
http://hg.openjdk.java.net/jdk8u/jdk8u/jdk/file/f7be58eb30bc/test/java/awt/grab/GrabOnUnfocusableToplevel/GrabOnUnfocusableToplevel.java
---------- END SOURCE ----------