Ignore <option> element while building accessibility tree when <selec…

…t> is hidden

https://bugs.webkit.org/show_bug.cgi?id=245578

Reviewed by Carlos Garcia Campos.

When we insert `AccessibilityObject`'s child, we check that its
`parentObject` is the `AccessiblityObject` we're inserting it into.

In normal circumstances `AccessibilityObject`'s subclass representing
`HTMLSelectElement` is `AccessibilityMenuList`. It creates
`AccessiblityMenuListPopup` as its only accessibility child. All
`HTMLSelectElement`'s node children accessibility objects are inserted
into the popup.

For non-multiple `HTMLSelectElement` the only possible node child class
that participates in accessibility tree is `HTMLOptionElement` with its
accessibility counterpart `AccessibilityMenuListOption`.
`AccessibilityMenuListOption`'s `parentObject` is set explicitly to
`AccessiblityMenuListPopup` when it's being inserted into one.

Situation changes when `HTMLSelectElement` is hidden but `aria-hidden`
attribute set to `false`
(like in `accessibility/aria-visible-element-roles.html` layout test).
In this case, we don't have a renderer object associated with
`HTMLSelectElement` and simply create a regular `AccessiblityNodeObject`
for it. Then we insert `AccessibilityMenuListOption` as
`AccessiblityNodeObject`'s child without setting its `parentObject`.
Thus, `child->parentObject() == this` assertion fails.

Since we can't present a menu without `HTMLSelectElement`'s renderer
anyway (and this is what Chromium does), it's safe to skip
`HTMLSelectElement` while building the accessibility tree in such cases.

* Source/WebCore/accessibility/AXObjectCache.cpp:
(WebCore::AXObjectCache::getOrCreate):

Canonical link: https://commits.webkit.org/254970@main

Source/WebCore/accessibility/AXObjectCache.cpp

@@ -741,6 +741,8 @@ AccessibilityObject* AXObjectCache::getOrCreate(Node* node)
         if (select->usesMenuList()) {
             if (!isOptionElement)
                 return nullptr;
+            if (!select->renderer())
+                return nullptr;
             object = AccessibilityMenuListOption::create(downcast<HTMLOptionElement>(*node));
         } else
             object = AccessibilityListBoxOption::create(downcast<HTMLElement>(*node));