[7u6] Review request for 7123957: Switch of Gnome theme ends up deadlocked in GTKEngine.native_switch_theme

[Dmitry Cherepanov]

This is a direct back port of the fix to 7u6.

Bug: http://bugs.sun.com/view_bug.do?bug_id=7123957

Webrev: http://cr.openjdk.java.net/~dcherepanov/7123957/webrev.0/

Thanks,
Dmitry