service worker: Change TEST_P to TEST_F after removing a flag.

Follow-up of r637231 which removed the test parameters that were
based on kServiceWorkerServicification.

Bug: 926114
Change-Id: I4c1bd72a451dd882f8553254ff4f42a27edf920b
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1498808
Reviewed-by: Hiroki Nakagawa <nhiroki@chromium.org>
Commit-Queue: Matt Falkenhagen <falken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#637603}
2 files changed