getSelectedUids() {
    if (this.shadowInputElem_.value.length > 0) {
      this.addAndMarkChip_(true);
    }
    var uids = new goog.structs.Map();
    this.forEachChild(function(chip) {
      if (!chip.isPassphrase()) {
        uids.set(chip.getValue(), true);
      }
    });

    return uids.getKeys();
  }
Returns a list with the selected UIDs.
@return {!Array.<string>} A list with the selected UIDs.