[Simon_says]

Big difference between an extension and being integrated into the browser. It's directly analogous to the difference between your OS being closed source and your OS being able to run closed source programs. The former is a liability; the latter is an ability that you grant to users to use the system the way they want.

[icebraining]

The CDM modules are not integrated with the browser. The browser only has an (open source) sandbox to run them.