Stop using CheckedPtr with DataTransfer. Use WeakPtr instead to generate more actionable crashes.
Pull request: https://github.com/WebKit/WebKit/pull/21824
Committed 272074@main (d2a203668918): <https://commits.webkit.org/272074@main> Reviewed commits have been landed. Closing PR #21824 and removing active labels.
<rdar://problem/119689593>