FSA: Add cleanup for WPT directory_tests
Currently, directory_tests cleanup before hand to be resilient against
other tests not cleaning up properly. But to be more courteous to other
tests, this CL adds cleanup for after the test as well.
Bug: 346991169
Change-Id: Iff4938926e31691aa3417177fe058a64e46eec0d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5871483
Reviewed-by: Christine Hollingsworth christinesm@chromium.org
Commit-Queue: Nathan Memmott memmott@chromium.org
Cr-Commit-Position: refs/heads/main@{#1358394}