<AWT Dev> [9] Review Request: JDK-8035168 [macosx] Remove CThreading class

[Petr Pchelko]

Hello, AWT Team.

Please review a simple cleanup fix: http://cr.openjdk.java.net/~pchelko/9/8035168/webrev/
For the bug: https://bugs.openjdk.java.net/browse/JDK-8035168

CThreading is not used and not needed as all required checks are made in native code. Let's remove it.

With best regards. Petr.