Hello. Please review a small fix for jdk 9.According to specification of java.awt.Checkbox.setState() we should not post ItemEvent after a call to this method. And this case is violated on the osx. The new event is postponed in the same way as in LWCheckboxPeer.setCheckboxGroup()
Bug: https://bugs.openjdk.java.net/browse/JDK-8074500 Webrev can be found at: http://cr.openjdk.java.net/~serb/8074500/webrev.00 -- Best regards, Sergey.
