www/chromium: update to 80.0.3987.149

The Chrome stable channel has been updated to 80.0.3987.149[1].

This update includes 13 security fixes, including 9 Sev:High reports from
external researchers.

[1]: https://chromereleases.googleblog.com/2020/03/stable-channel-update-for-desktop_18.html

PR: 245019
Approved by: jrm
Security: yes
Differential Revision: https://reviews.freebsd.org/D24169