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

This reverts commit e226149af1b3f003b5d3f59e19ee17bef7419c42.

Reason for revert: 

`ProfileWithoutMediaCacheBrowserTest.DeleteMediaCache` and `ProfileWithoutMediaCacheBrowserTest.DeleteIsolatedAppMediaCache` have been failing, apparently since they were added by this CL.

They were added here: https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac10.11%20Tests/28016 (which failed to actually run `browser_test`) and have been failing consistently since https://ci.chromium.org/p/chromium/builders/luci.chromium.ci/Mac10.11%20Tests/28018.


Original change's description:
> 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).
> 
> Bug: 789657
> Change-Id: I45e8f8c6e346a1fa7d05b0bea3e8b001d7dc41e1
> Reviewed-on: https://chromium-review.googlesource.com/1130162
> Reviewed-by: Maks Orlovich <morlovich@chromium.org>
> Commit-Queue: Matt Menke <mmenke@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#574296}

TBR=mmenke@chromium.org,morlovich@chromium.org

Change-Id: Ibc519750f00ad7e698d279af6baffe77b32d30be
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 789657, 862945
Reviewed-on: https://chromium-review.googlesource.com/1134886
Reviewed-by: Mike West <mkwst@chromium.org>
Commit-Queue: Mike West <mkwst@chromium.org>
Cr-Commit-Position: refs/heads/master@{#574513}
2 files changed