https://bugs.webkit.org/show_bug.cgi?id=17513 has been closed,now we can focus area object,but can't show focus ring,I think it's maybe a css problem,IE or firefox can display focus ring via TAB.
*** Bug 48438 has been marked as a duplicate of this bug. ***
Confirmed fixed in WebKit Nightly r101106. Confirmed fixed in WebKit Nightly r107164. Confirmed fixed in Google Chrome 17.0.963.46 (Official Build 119351) (WebKit 106042). Confirmed regressed in Google Chrome 19.0.1035.0 (Official Build 120973) canary (WebKit 107065).