constructor(keys, callback) {
    super(
        templates.importKeyConfirm({
          promptImportKeyConfirmLabel:
              chrome.i18n.getMessage('promptImportKeyConfirmLabel'),
          keys: keys,
          secretKeyDescription: chrome.i18n.getMessage('secretKeyDescription'),
          publicKeyDescription: chrome.i18n.getMessage('publicKeyDescription'),
          keyFingerprintLabel: chrome.i18n.getMessage('keyFingerprintLabel')
        }),
        callback, dialogs.InputType.NONE, '',
        chrome.i18n.getMessage('promptOkActionLabel'),
        chrome.i18n.getMessage('actionCancelPgpAction'));
  }
@param {!e2e.openpgp.Keys} keys The keys to import.
@param {!function(string=)} callback The callback where the user's
    input must be passed.