In order to avoid showing media controls at a different size than that of the video when we've received enough information to determine whether it's audio or video and what the video frame size is, we do not show any UI until we have enough information to show the controls in their correct initial state. This works great with local files and fast-loading files, but does not work well with invalid files, which never load and fail to ever show any UI, and files that load slowly where there is no visible feedback that content will be visible.
<rdar://problem/32178119>
Created attachment 313349 [details] Patch
Committed r218600: <http://trac.webkit.org/changeset/218600>