Revert of Add HardStopGradientBench.cpp (patchset #3 id:40001 of https://codereview.chromium.org/2131643002/ )

Reason for revert:
Segfaulting on HardStopGradientBench; didn't allocate enough stack memory for color/position arrays.

Original issue's description:
> Add HardStopGradientBench.cpp
>
> BUG=skia:
> GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2131643002
>
> Committed: https://skia.googlesource.com/skia/+/d0d652e0e0cb4bcecb7ccac9f4f4831fcaccdc45

TBR=bsalomon@google.com
# Skipping CQ checks because original CL landed less than 1 days ago.
NOPRESUBMIT=true
NOTREECHECKS=true
NOTRY=true
BUG=skia:

Review-Url: https://codereview.chromium.org/2140603003