Function cef_initialize 

pub unsafe extern "C" fn cef_initialize(
    args: *const cef_main_args_t,
    settings: *const _cef_settings_t,
    application: *mut cef_app_t,
    windows_sandbox_info: *mut c_void,
) -> c_int

This function should be called on the main application thread to initialize the CEF browser process. The |application| parameter may be NULL. A return value of true (1) indicates that it succeeded and false (0) indicates that it failed. The |windows_sandbox_info| parameter is only used on Windows and may be NULL (see cef_sandbox_win.h for details).