Eliminate the duplicate functionality,
and better testing for the bench builders.
Change-Id: If20e52107738903f854aec431416e573d7a7d640
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/218041
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
