After the change-set <https://trac.webkit.org/changeset/267498> landed, an extension to diagnostics is issued when required, so the unconditional rule can be removed from the WebContent sandbox.
Created attachment 409574 [details]
Created attachment 409575 [details]
Created attachment 409594 [details]
Thanks for reviewing!
Created attachment 409690 [details]
This is being landed without the test, since the test results are different in internal OS variants.
Committed r267569: <https://trac.webkit.org/changeset/267569>
All reviewed patches have been landed. Closing bug and clearing flags on attachment 409690 [details].