Installing time zone data on MariaDB 10.0
I'm concerned that installing one of these (probably would choose mariadb-server-5.5) would conflict with our currently-installed version of MariaDB (10.0.17-MariaDB-1~precise-log).


Ubuntu Precise was released 12.04. It's super ridiculous old, and it was when you asked the question. That's why the version of MariaDB was so old too. MariaDB dropped support for precise in 10.0.31. Because you're running on an unofficial in Debian/Ubuntu's eyes version of MariaDB, it's not guaranteed to work with the system. 

All of that said, the question is essentially who packaged your MariaDB. It seems likely you got it from MariaDB upstream. So while you have a workaround, the question is better phrased like this


Where does MariaDB install mysql_tzinfo_to_sql?


Clearly it's not in your path, you can find it by


running the package you downloaded through dpkg -c.
using apt-file
Running: sudo updatedb; locate mysql_tzinfo_to_sql;