fn obtain_a_browsing_context(
script_window_proxies: &ScriptWindowProxies,
id: BrowsingContextId,
destination_origin: &MutableOrigin,
) -> Option<DomRoot<WindowProxy>>fn obtain_a_browsing_context(
script_window_proxies: &ScriptWindowProxies,
id: BrowsingContextId,
destination_origin: &MutableOrigin,
) -> Option<DomRoot<WindowProxy>>