Currently, it always show 0, since it queries it after m_writer.finalize() which moves it away.
Created attachment 442090 [details] Patch
Comment on attachment 442090 [details] Patch r=me
Committed r284690 (243410@main): <https://commits.webkit.org/243410@main> All reviewed patches have been landed. Closing bug and clearing flags on attachment 442090 [details].
<rdar://problem/84552557>