Delete the media cache(s) when using a single combined HTTP cache.

This is so that I can try increasing the media cache size in experiments
without increasing Chrome's profile size (Except possibly for profiles
that have never been used to play video).

This is a relant of
https://chromium-review.googlesource.com/c/chromium/src/+/1130162, with
re-worked tests.

Bug: 789657
Change-Id: I057e2e657572e21732610aefc468550e58fabf77
Reviewed-on: https://chromium-review.googlesource.com/1145137
Reviewed-by: Maks Orlovich <morlovich@chromium.org>
Commit-Queue: Matt Menke <mmenke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577595}
2 files changed