See https://github.com/whatwg/fetch/issues/1135 and https://github.com/web-platform-tests/wpt/pull/27100. Having different consumers of those objects use different sources is the beginning of a security bug of sorts.
<rdar://problem/73343155>
Pull request: https://github.com/WebKit/WebKit/pull/12376
Committed 264054@main (cd292c4f5558): <https://commits.webkit.org/264054@main> Reviewed commits have been landed. Closing PR #12376 and removing active labels.