export declare function sync_fullscreen(opts: {
    get_wrapper: () => HTMLDivElement | undefined;
    get_fullscreen: () => boolean;
    set_fullscreen: (fullscreen: boolean) => void;
    bg_css_var: string;
    on_request_error?: (err: Error) => void;
    on_change?: (fullscreen: boolean) => void;
}): void;