Comparing with the previous patch(https://bugs.webkit.org/show_bug.cgi?id=81343), the cover area is calculated when the trajectory vector is not zero.
Created attachment 136201 [details] proposal.patch
Comment on attachment 136201 [details] proposal.patch Clearing flags on attachment: 136201 Committed r113967: <http://trac.webkit.org/changeset/113967>
All reviewed patches have been landed. Closing bug.