It appears that the cookie's expiry time is not round-tripping correctly, and is always off by one.
<rdar://problem/39186578>
Created attachment 337222 [details] Patch
Comment on attachment 337222 [details] Patch Attachment 337222 [details] did not pass mac-wk2-ews (mac-wk2): Output: http://webkit-queues.webkit.org/results/7209214 New failing tests: accessibility/smart-invert-reference.html
Created attachment 337238 [details] Archive of layout-test-results from ews106 for mac-sierra-wk2 The attached test failures were seen while running run-webkit-tests on the mac-wk2-ews. Bot: ews106 Port: mac-sierra-wk2 Platform: Mac OS X 10.12.6
Comment on attachment 337222 [details] Patch Clearing flags on attachment: 337222 Committed r230286: <https://trac.webkit.org/changeset/230286>
All reviewed patches have been landed. Closing bug.