I just checked my records.
Computer purchased: 2014 July Ubuntu 14.04 installed: 2014 July chromium-codecs-ffmpeg-extra 1st upgraded: 2014 August
So it seems that this package was installed on my system from the get go.
Today, I decided to check whether or not this package is supported by Ubuntu only to find to my surprise that it is not! Why then is it installed, seemingly by default, on Ubuntu systems?