Function: view-return-to-alist-update

Update `view-return-to-alist' of buffer BUFFER.
Remove from `view-return-to-alist' all entries referencing dead
windows. Optional argument ITEM non-nil means add ITEM to
`view-return-to-alist' after purging. For a description of items
that can be added see the RETURN-TO-ALIST argument of the
function `view-mode-exit'. If `view-return-to-alist' contains an
entry for the selected window, purge that entry from
`view-return-to-alist' before adding ITEM.