Remove "filesystem" URL scheme

[annevk]

As far as I know there's only one implementation. Also need to add historical tests.

[M-ZubairAhmed]

hi @annevk can you please tell me more about this issue, i would like to give this a try. Thank you

[annevk]

This would require removing the three occurences of "filesystem" in the standard, along with corresponding text for the third instance.

(You can ignore "needs tests". I'm not sure how I imagined to test for this. I don't think that's actually possible.)

[M-ZubairAhmed]

thank you , will surely look into it this weekend. Also please go easy on me, i have very rarely collaborated in large public project 🐌

[domenic]

I think this could be tested, by creating a fetchable file using the Chrome-only filesystem APIs and then trying to fetch() it.

[annevk]

As a Chrome-only test? That doesn't seem like a good fit for wpt.

[domenic]

Well, we could make the test also pass if those Chrome-only APIs weren't present, I guess. Like, we'd have a historical test saying those Chrome-only APIs weren't present, then a second historical test saying "if they are present, filesystem URLs should not work".

[annevk]

Filed web-platform-tests/wpt#15525 on that idea.