<Swing Dev> [9] Review request for 8156128: Tests for [AWT/Swing] Conditional support for GTK 3 on Linux

[Yuri Nesterenko]

Colleagues,

could you please review the tests for the new jdk.gtk.version property?

Webrev is http://cr.openjdk.java.net/~yan/8156128/webrev.00/
CR is https://bugs.openjdk.java.net/browse/JDK-8156128

A couple of interesting scenarios would require some system preparation
(read: hacks) and are not intended for the regular use.
See https://bugs.openjdk.java.net/browse/JDK-8156121 filed
after one of such special runs.

Thanks,
-yan