When a media file used in a <video> element loads very quickly, it is possible for the AVFoundation backend state machine to miss a state transition and think it is not loaded. <rdar://problem/9330567>
Created attachment 92970 [details] Proposed patch.
http://trac.webkit.org/changeset/86163
Revision r86163 cherry-picked into qtwebkit-2.2 with commit f0a236c <http://gitorious.org/webkit/qtwebkit/commit/f0a236c>