force 1.0f roundtrip through invert by tweaking e

Rewrite our stock inverse sRGB numbers using invert(sRGB),
and test that it stays that way.

Just had a feeling this all needs a guard, so guarded.
(Might even need to widen it to cover the previous CL.)

Change-Id: I6e4a1d212005c257bf5c4fa6137c4897f40e1f31
Reviewed-by: Mike Klein <>
Commit-Queue: Mike Klein <>
46 files changed