[webkit-dev] Intent to remove FileError

[Tetsuharu OHZEKI]

Hi WebKitten,

I'm not sure that we have a kind of this process,
but I think this mail might be helpful for some developers relying on
this legacy interface.

## Summary

I removed `FileError` as a web-exposed interface.
By this change, `FileReader.error` uses `DOMException` instead.

## Explanation

AFAIK, `FileError` was used in the earlier spec about 10 years ago.
https://www.w3.org/TR/2010/WD-FileAPI-20101026/

And it had been changed to `DOMError` but it was also replaced to
`DOMException` in 2017.
https://github.com/w3c/FileAPI/issues/11

Other browsers followed this spec change several years ago,
but WebKit is still exposing this interface.

* Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1120178
* Chromium: https://bugs.chromium.org/p/chromium/issues/detail?id=460725

Thus I removed FileError as a web-exposed interface in bug 213117.
https://bugs.webkit.org/show_bug.cgi?id=213117

I plan to remove internal usages for FileError.{h,cpp} in bug 213119.
https://bugs.webkit.org/show_bug.cgi?id=213119

--
Tetsuharu OHZEKI
tetsuharu.ohzeki at gmail.com