An RPC handler that can serve a client whose socket was created by the caller rather than
accepted from the websocket server. Only the process that owns the server (main) implements this;
it is how a renderer's MessagePort-backed connection joins the same registry as the websocket
clients.
An RPC handler that can serve a client whose socket was created by the caller rather than accepted from the websocket server. Only the process that owns the server (main) implements this; it is how a renderer's MessagePort-backed connection joins the same registry as the websocket clients.