Background tabs that are hosted in window server will flash before painting when they first become active. It only happens on the first activation. <rdar://problem/11518154>
Created attachment 144125 [details] Patch
Comment on attachment 144125 [details] Patch We're not sure this is quite right yet.
Comment on attachment 144125 [details] Patch Setting back to r? after going through this with Anders.
Comment on attachment 144125 [details] Patch This is fine for now.
Thanks Anders! http://trac.webkit.org/changeset/118559