message: Fixed keys is optional
diff: @@ -43,7 +43,10 @@ function storageGet (storageArea) {
  * @see https://developer.chrome.com/extensions/storage#type-StorageArea
  */
  return function get (keys, cb) {
  - if (typeof cb === 'function') {
  + if (typeof keys === 'function') {
  + cb = keys
  + return chrome.storage[storageArea].get(cb)
  + } else if (typeof cb === 'function') {
  return chrome.storage[storageArea].get(keys, cb)
  } else {
  return new Promise((resolve, reject) => {
  