To do this, we need to implement the CenterSelectionInVisibleArea editor command in WebCore.
Created attachment 100893 [details]
I forgot that besides scrolling the selection into view, I also need to flash the find indicator (bounce the yellow bubble around the selection) when that command is triggered. I'm going to send a new patch, and since the find indicator is not part of WebCore, I might as well just handle everything within WebKit.
Created attachment 101032 [details]
Patch (2nd version)