On the Mac platform, we need to spin the run loop while making synchronous calls to avoid VoiceOver hanging. On iOS, this not needed due to architectural differences
<rdar://problem/16519544>
<rdar://problem/16507295>
<rdar://problem/16519553>
Created attachment 228564 [details] patch
Created attachment 228566 [details] patch
http://trac.webkit.org/changeset/166769