Combines the two boolean options into a single tri-state enum. Old GLSL
option is still present (temporarily) until Chrome is switched over.
Also add a type tag for cached program binaries, so we can safely
detect cache entries of the wrong type.
Change-Id: I0ddeefa9180b27bc2c46e2e7b77e6c9cdf4a730a
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/238856
Commit-Queue: Brian Osman <brianosman@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
a66081d943