hg: openjfx/8u-dev/rt: 8172554: [macos] deadlock on JFXPanel startup

[semyon.sadetsky at oracle.com]

Changeset: bf7a9e67c114
Author:    ssadetsky
Date:      2017-06-15 15:35 -0700
URL:       http://hg.openjdk.java.net/openjfx/8u-dev/rt/rev/bf7a9e67c114

8172554: [macos] deadlock on JFXPanel startup
Reviewed-by: kcr

! modules/swing/src/main/java/javafx/embed/swing/JFXPanel.java
+ tests/system/src/test/java/javafx/embed/swing/JFXPanelTest.java