Add support for hosting layers in the window server in WebKit2
<rdar://problem/10400246>
Created attachment 130190 [details] Patch
Comment on attachment 130190 [details] Patch Attachment 130190 [details] did not pass win-ews (win): Output: http://queues.webkit.org/results/11819166
Committed r109804: <http://trac.webkit.org/changeset/109804>