TextTrackCue should get its document for its ActiveDOMObject base class instead of requiring an extra data member to store it.
<rdar://93512736>
Pull request: https://github.com/WebKit/WebKit/pull/787
Committed r294498 (250757@main): <https://commits.webkit.org/250757@main> Reviewed commits have been landed. Closing PR #787 and removing active labels.