Created attachment 59091 [details] a repro; it should be styled, but it isn't. <progress> should be styled when some style is given for ::-webkit-progress-bar-value pseudo class. Currently it is styled only if both progress and ::-webkit-progress-bar-value has some style properties.
Created attachment 59351 [details] patch v0
Comment on attachment 59351 [details] patch v0 OK. Because native progress bar on Mac is animated, we should skip this test on Mac.
Committed r61993: <http://trac.webkit.org/changeset/61993>
http://trac.webkit.org/changeset/61993 might have broken Qt Linux Release