Revert "call skcms_OptimizeForSpeed()"

This reverts commit 3b8feb331a11989fdd82c2d8d18e576df98e8895.

Reason for revert: darks too bright

Original change's description:
> call skcms_OptimizeForSpeed()
> 
> I've guarded src and dst separately, so that we can land,
> rebaseline just the src change, and then later (when it
> does something), rebaseline optimizing dst separately.
> 
> Small threshold tweak to keep a unit test passing.
> 
> Change-Id: I57cc43c54b6065f58fa8f9448ea1d73fc42505f0
> Reviewed-on: https://skia-review.googlesource.com/123181
> Commit-Queue: Mike Klein <mtklein@chromium.org>
> Reviewed-by: Brian Osman <brianosman@google.com>

TBR=mtklein@chromium.org,brianosman@google.com

Change-Id: I23e59d4dc711e8b112e70f31a5c9abad67551bcd
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://skia-review.googlesource.com/123361
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
2 files changed