[pathkit] Clean up perf/test init

This will hopefully help with flakiness.

Bug: skia:8810
Change-Id: Id2fa9abcc0e95f0cf8b08557215766b4f9c57478
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/200047
Reviewed-by: Ben Wagner <benjaminwagner@google.com>
13 files changed