GitLab

arm devices require the OPUS_FIXED_POINT. This define got lost at some
point. Add a public_dep so the media_unittests gets the necessary
config.

BUG=672352
TEST=gn desc out/ //media:media_unittests

Review-Url: https://codereview.chromium.org/2562513003
Cr-Commit-Position: refs/heads/master@{#437628}