GitLab

Converts most logic in media.gyp to BUILD.gn files.

Most everything but android and cdm code has been converted. Next step is to break these up into smaller BUILD.gn files per subdirectory.

All hail GN. orz

BUG=none
R=brettw@chromium.org, dalecurtis@chromium.org

Review URL: https://codereview.chromium.org/268713006

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@282448 0039d316-1c4b-4281-b951-d872f2087c98