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}
2 files changed