Code Review Request for RT-35956: Add a stopgap fix to improve mesh update performance for limited use cases that doesn't do 3d lighting in the scene

[Chien Yang]

Kevin and Vadim,

Please review this very limited and guarded fix as a temporary solution 
till we have a better API to support dynamic mesh update.
More information about performance is captured in the JIRA.

Webrev: http://cr.openjdk.java.net/~ckyang/RT-35956/webrev.00/
JIRA: https://javafx-jira.kenai.com/browse/RT-35956

Thanks,
- Chien