[w3c/FileAPI] Include MediaStream overload for createObjectURL (#100)

Currently [the MSE spec](https://github.com/w3c/media-source/issues/211) adds overload for createObjectURL using partial interface, but [the Web IDL spec says](https://heycam.github.io/webidl/#idl-overloading):

>Operations must not be overloaded across interface, partial interface, interface mixin, and partial interface mixin definitions.

We should directly include the overload in the original definition.

-- 
You are receiving this because you are subscribed to this thread.
Reply to this email directly or view it on GitHub:
https://github.com/w3c/FileAPI/issues/100