Add factory functions to distinguish between when the owner of the File
wants to transfer ownership to the new IPC object (adopt) or to send a
copy of the same fd to the IPC peer (clone).
This behavior is more intuitive than the previous behavior. Previously,
an IPC::File would default to a shallow clone of the file descriptor,
only *actually* calling dup(2) for the fd when encoding or it into an
IPC MessageBuffer. Now the dup(2) for the fd is explicit in the clone_fd
factory function.
Instead of spawning these processes from the WebContent process, we now
create them in the Browser chrome.
Part 1/N of "all processes are owned by the chrome".
We now create a WorkerAgent for the parent context, which is currently
only a Window. Note that Workers can have Workers per the spec.
The WorkerAgent spawns a WebWorker process to hold the actual
script execution of the Worker. This is modeled with the
DedicatedWorkerHost object in the WebWorker process.
A start_dedicated_worker IPC method in the WebWorker IPC creates the
WorkerHost object. Future different worker types may use different IPC
messages to create their WorkerHost instance.
This implementation cannot yet postMessage between the parent and the
child processes.
Co-Authored-By: Andreas Kling <kling@serenityos.org>
