add (e)sRGB gradients to P3 GM

At the moment I'm actually a bit confused about
why the new pair of gradients appear to interpolate
in P3 when drawn in --config 8888.

--config gl works as I'd expect, interpolating the
existing gradients in P3 and the new gradients in
sRGB.

Change-Id: I74b77d834b495a7545753b76c8fd8ecaeb5c7b70
Reviewed-on: https://skia-review.googlesource.com/c/161586
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
1 file changed