ServiceWorker: Run ServiceWorkerContextTest.DeleteAndStartOver on disk
Currently DeleteAndStartOver() is tested in memory storage (MemEnv)
supported by LevelDB for performance, but it seems preferable to test
it on real environment, that is, on disk storage because the recovery
process can be affected by characteristics of lower filesystem.
BUG=
468926
TEST=content_unittests --gtest_filter=ServiceWorkerContextTest.DeleteAndStartOver
Committed:
https://crrev.com/e47602102bf2c4c32af751e13cf08aab639c3576
Cr-Commit-Position: refs/heads/master@{#322346}