In JDK-8247332 we are enabling usage of CVDisplayLink to blit to CAMetalLayer.

https://developer.apple.com/library/archive/qa/qa1385/_index.html doesnt mention about using setNeedsDisplay when we use CVDisplayLink. But in our current OpenGL implementation we always drive blitting to CALayer in Appkit thread.

Preliminary testing of CVDisplayLink with or without setNeedsDisplay has shown no difference in output.
Verify whether we need to use setNeedsDisplay to blit or directly call blit routine.