flex-grow should be 1 when omitted from flex shorthand
Created attachment 165443 [details] Patch
http://www.w3.org/TR/css3-flexbox/#flex-common is very explicit about this.
Comment on attachment 165443 [details] Patch Clearing flags on attachment: 165443 Committed r129414: <http://trac.webkit.org/changeset/129414>
All reviewed patches have been landed. Closing bug.