It passes/times out as per https://webkit-test-results.webkit.org/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=cache-storage
Created attachment 323692 [details] Patch
Comment on attachment 323692 [details] Patch Clearing flags on attachment: 323692 Committed r223288: <https://trac.webkit.org/changeset/223288>
All reviewed patches have been landed. Closing bug.
<rdar://problem/34981451>
Reopened for investigation
Test no longer seems flaky.