Remove redundant tests to make DM a little faster

This should help with some of the slow down caused by
https://codereview.chromium.org/1907593004.

BUG=skia:5181
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1923533002

Review URL: https://codereview.chromium.org/1923533002
1 file changed