Function emscripten_sys::emscripten_set_webglcontextlost_callback

pub unsafe extern fn emscripten_set_webglcontextlost_callback(target: *const c_char,
                                                              userData: *mut c_void,
                                                              useCapture: c_int,
                                                              callback: em_webgl_context_callback)
                                                              -> c_int