[9] Code Review For 8144585: Encapsulate JavaFX impl_* implementation methods

[Chien Yang]

Hi all,

Please review the proposed fix:

JIRA: https://bugs.openjdk.java.net/browse/JDK-8144585
Webrev: http://cr.openjdk.java.net/~ckyang/JDK-8144585/webrev.00/

Thanks,
- Chien