Whatever behavior difference is needed should not be down here in WebCore.
<rdar://problem/82602727>
This still exist: https://github.com/WebKit/WebKit/blob/b3a5c931e34b75897600609a07df70e3dc0924cc/Source/WebCore/dom/Node.cpp#L2534 https://github.com/WebKit/WebKit/blob/b3a5c931e34b75897600609a07df70e3dc0924cc/Source/WebCore/dom/Node.cpp#L2572