Second parameter to History.pushState() / replaceState() should be mandatory: - https://html.spec.whatwg.org/multipage/browsers.html#history-3 Firefox and Chrome agree with the specification.
Created attachment 284666 [details] Patch
Created attachment 284669 [details] Patch
Comment on attachment 284669 [details] Patch Clearing flags on attachment: 284669 Committed r203760: <http://trac.webkit.org/changeset/203760>
All reviewed patches have been landed. Closing bug.