Revert "Encapsulate GL version and standard into a struct and enum." Linux didn't like compiling this. This reverts commit 03f589122ed796060f1345f9ccfc64455c547fef. Change-Id: Ifd0824caeb02791b4acc5e4bca330ecdc8164b11 Reviewed-on: https://chromium-review.googlesource.com/273583 Reviewed-by: Geoff Lang <geofflang@chromium.org> Tested-by: Geoff Lang <geofflang@chromium.org>