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. Returns true (1) if initialization succeeds. Returns false (0) if initialization fails or if early exit is desired (for example, due to process singleton relaunch behavior). If this function returns false (0) then the application should exit immediately without calling any other CEF functions except, optionally, CefGetExitCode. The |windows_sandbox_info| parameter is only used on Windows and may be NULL (see cef_sandbox_win.h for details).