support PQ/HLG in skcms_Transform()

A little more than you might think to support PQ/HLG destinations,
but mostly straightforward.

There are a lot of precision and roundtripping things I'd like to
work out at some point, but I think this all roughly works now.

Bug: chromium:960620
Change-Id: I2c8dcb93c5409f14e4acbaadc0b9ec3a59237d6e
Commit-Queue: Mike Klein <>
Reviewed-by: Brian Osman <>
3 files changed