We load these 2 iframes to do stuff from the https://marketplace.firefox.com/ origin. Unfortunately we don't compress the <script> that they contain. In addition, because of the security concerns with gzip and https (BREACH), we don't automatically enable gzip on non-API pages, but we should force it on those, since they don't contain any dynamic/secret content anyway. Doing both, or at least one of those, should reduce the size a little. iframe-install.html is close to 6KB at the moment, and it's not loaded from the CDN (it can't, needs the m.f.c origin).

I filed bug 960752 and then bug 987403 for this. We should just gzip at the very least all of Fireplace's HTML.

Ok, modifying summary per comment 1. This bug is now only about minifying the <script> in those 2 pages. Since bug 987403 will enable gzip on those pages I don't believe minifying the scripts is going to be that much important, but let's revisit the issue once bug 987403 lands.