makeField_(container, name, setup, onChange, isTextArea) {
    container.addRow(/* labelString= */ null, /* tooltipString= */ null);
    const input =
        new shakaDemo.TextInput(container, name, onChange, isTextArea);
    input.extra().textContent = name;
    setup(input.input(), input.container());
  }
A utility to simplify the creation of fields on the dialog.
@param {!shakaDemo.InputContainer} container
@param {string} name
@param {function(!HTMLInputElement, !Element)} setup
@param {function(!Element, !shakaDemo.Input)} onChange
@param {boolean=} isTextArea
@private