function createEnterARButton(onClick, xrMode) {
  var arButton;
  var wrapper;

  // Create elements.
  wrapper = document.createElement('div');
  wrapper.classList.add(ENTER_AR_CLASS);
  if (xrMode) {
    wrapper.classList.add('xr');
  }
  wrapper.setAttribute(_constants_index_js__WEBPACK_IMPORTED_MODULE_1__.AFRAME_INJECTED, '');
  arButton = document.createElement('button');
  arButton.className = ENTER_AR_BTN_CLASS;
  arButton.setAttribute('title', 'Enter AR mode with a headset or handheld device.');
  arButton.setAttribute(_constants_index_js__WEBPACK_IMPORTED_MODULE_1__.AFRAME_INJECTED, '');
  if (_utils_index_js__WEBPACK_IMPORTED_MODULE_2__.device.isMobile()) {
    applyStickyHoverFix(arButton);
  }
  // Insert elements.
  wrapper.appendChild(arButton);
  arButton.addEventListener('click', function (evt) {
    onClick();
    evt.stopPropagation();
  });
  return wrapper;
}
Create a button that when clicked will enter into AR mode

Structure: <div><button></div>

@param {function} onClick - click event handler
@returns {Element} Wrapper <div>.