Several media elements, e.g., the MediaControlTextTrackContainerElement, are not initialized with their Shadow DOM Pseudo Id (e.g., the "-webkit-media-text-track-container") value. When the pseudoId is not set, the Web Inspector can be confusing, because the element only displays as a "<div>", with nothing showing it's functional purpose in the media control hierarchy. We should set the pseudo Id at construction time so that the object displays properly.
Created attachment 228015 [details] Patch
It looks like inside WebCore itself, we call "shadowPseudoId()" to retrieve the value. However, the WebInspector and other pure JS clients call through the attribute access logic which only gets set up if a call to "setPseudo" is made at some point. It would probably be wise to coalesce these two "separate but equal" concepts of shadow ID.
Comment on attachment 228015 [details] Patch Clearing flags on attachment: 228015 Committed r166395: <http://trac.webkit.org/changeset/166395>
All reviewed patches have been landed. Closing bug.