Was initially 16, which is a bit low as I've just discovered with a 17-button-device in hand.
Created attachment 119327 [details]
Please wait for approval from firstname.lastname@example.org before submitting because this patch contains changes to the Chromium public API.
Comment on attachment 119327 [details]
Clearing flags on attachment: 119327
Committed r102887: <http://trac.webkit.org/changeset/102887>
All reviewed patches have been landed. Closing bug.