function enqueueTextContent(parentID, textContent) {
  // NOTE: Null values reduce hidden classes.
  updateQueue.push({
    parentID: parentID,
    parentNode: null,
    type: ReactMultiChildUpdateTypes.TEXT_CONTENT,
    markupIndex: null,
    content: textContent,
    fromIndex: null,
    toIndex: null
  });
}
Enqueues setting the text content.

@param {string} parentID ID of the parent component.
@param {string} textContent Text content to set.
@private