Review request for 7131793: [macosx] some cleanup in OGL pipeline code

[Dmitry Cherepanov]

Hello,

Here's some changes to remove some stale code from the OGL pipeline. 
This code has been introduced as a part of the initial implementation 
for CALayer-based rendering and disabled by the changes for MACOSX_PORT-766.

http://cr.openjdk.java.net/~dcherepanov/7131793/webrev.1/

Thanks,
Dmitry