Select-only Combobox Example: Fix scroll event listener bug (pull #2723)

Fixes #2719.
Scrollbar on the list for select only would close when user would click on it.

---

Co-authored-by: Andrea N. Cardona <[email protected]>

Author: ariellalgilmore

content/patterns/combobox/examples/js/select-only.js

@@ -195,6 +195,7 @@ Select.prototype.init = function () {
 
   // add event listeners
   this.comboEl.addEventListener('blur', this.onComboBlur.bind(this));
+  this.listboxEl.addEventListener('focusout', this.onComboBlur.bind(this));
   this.comboEl.addEventListener('click', this.onComboClick.bind(this));
   this.comboEl.addEventListener('keydown', this.onComboKeyDown.bind(this));
 
@@ -239,10 +240,9 @@ Select.prototype.getSearchString = function (char) {
   return this.searchString;
 };
 
-Select.prototype.onComboBlur = function () {
-  // do not do blur action if ignoreBlur flag has been set
-  if (this.ignoreBlur) {
-    this.ignoreBlur = false;
+Select.prototype.onComboBlur = function (event) {
+  // do nothing if relatedTarget is contained within listboxEl
+  if (this.listboxEl.contains(event.relatedTarget)) {
     return;
   }