ShellSettleRegistrar typedef
ShellSettleRegistrar =
VoidCallback Function(VoidCallback settle)
Registers the shell's synchronous settle with its host (spec 12a D2,
plan 12a P-4): the host calls settle before a flow reads or replaces
the document. Returns the function that withdraws the registration; the
shell calls it on dispose, and it withdraws only settle itself, since
a swap builds the next shell before the old one is disposed.
Implementation
typedef ShellSettleRegistrar = VoidCallback Function(VoidCallback settle);