Revert of Created new target unit_tests in //media/formats. (patchset #4 id:60001 of https://codereview.chromium.org/2888523002/ )

Reason for revert:
broke official builds: https://crbug.com/737857 tried to fix here: https://codereview.chromium.org/2966573002/ but that's turning out to be complicated

Original issue's description:
> Created new target unit_tests in //media/formats.
>
> Created unit_tests target in //media/formats/BUILD.gn and moved the
> respective unit_test changes from //media/BUILD.gn to
> //media/formats/BUILD.gn.
>
> BUG=613033
>
> R=jrummell@chromium.org, xhwang@chromium.org
>
> Review-Url: https://codereview.chromium.org/2888523002
> Cr-Commit-Position: refs/heads/master@{#474743}
> Committed: https://chromium.googlesource.com/chromium/src/+/b0fc11f9713bc1e54f94a2f23690cfc565f73ea0

TBR=dalecurtis@chromium.org,a.suchit@chromium.org,jrummell@chromium.org,xhwang@chromium.org,a.suchit@samsung.com
# Not skipping CQ checks because original CL landed more than 1 days ago.
BUG=613033

Review-Url: https://codereview.chromium.org/2967543004
Cr-Commit-Position: refs/heads/master@{#483610}
2 files changed