​

function objectProperties(object, result = {}) {

  let proto = object;

  while ((proto = Object.getPrototypeOf(proto)) !== Object.prototype) {

    for(const name of Object.getOwnPropertyNames(proto)) {

      result[name] = name;

    }

  }

  return result;

}

objectProperties(new MediaSource());

​

function objectProperties(object, result = {}) {

  let proto = object;

  while ((proto = Object.getPrototypeOf(proto)) !== Object.prototype) {

    for(const descriptor in Object.getOwnPropertyDescriptors(proto)) {

      result[descriptor] = descriptor;

    }

  }

  return result;

}

objectProperties(new MediaSource());