This is a public service announcement. There is a top-level directory in mozilla-central (and similar repos) called “other-licenses”. Don’t put any more code in it. Really. There’s now even a README saying so.
Longer version: this directory is not for non-MPLed code, it’s for non-MPL-compatible code, of which we have very little. There is some stuff in there which shouldn’t be, but let’s not make it worse, OK? :-) Keep your code where it logically lives; don’t make your life harder than it needs to be. If you really think you are importing code which needs to be in there, you should be talking to email@example.com first (as with any code import) and explicitly saying you think that this is where it should go, so they can tell you that you’re wrong ;-)