Resync web-platform-tests/notifications from upstream.
Created attachment 404009 [details] Patch
Comment on attachment 404009 [details] Patch rs=me
Created attachment 404026 [details] Patch
Committed r264257: <https://trac.webkit.org/changeset/264257> All reviewed patches have been landed. Closing bug and clearing flags on attachment 404026 [details].
<rdar://problem/65380509>