[webkit-reviews] review requested: [Bug 4377] visibility:hidden can't be overriden in child for positioned element : [Attachment 10790] another updated patch

[bugzilla-request-daemon at opendarwin.org]

Antti Koivisto <koivisto at iki.fi> has asked  for review:
Bug 4377: visibility:hidden can't be overriden in child for positioned element
http://bugzilla.opendarwin.org/show_bug.cgi?id=4377

Attachment 10790: another updated patch
http://bugzilla.opendarwin.org/attachment.cgi?id=10790&action=edit

------- Additional Comments from Antti Koivisto <koivisto at iki.fi>
- update patch to current webkit
- added m_hasVisibleDescendant bit to track visibility of child layers,
avoiding the need to crawl through the entire layer tree to find visible layers