Make the Object class independent of the GL version.

Bug 18962347

Change-Id: Ica99629bf58e799d6552d4a92ce3ae3eff57da27
Reviewed-on: https://swiftshader-review.googlesource.com/1880
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>