MediaPlayer should inherit from ThreadSafeRefCountedAndCanMakeThreadSafeWeakPtr<>. It currently inherits from ThreadSafeRefCounted<> and CanMakeWeakPtr<> separately.
<rdar://problem/110955978>
Pull request: https://github.com/WebKit/WebKit/pull/15080
Committed 265366@main (f9b1212d5dad): <https://commits.webkit.org/265366@main> Reviewed commits have been landed. Closing PR #15080 and removing active labels.