AX ITM: ARIATreeItemContent, ARIATreeRows, and DisclosedRows properties need to be...

AX ITM: ARIATreeItemContent, ARIATreeRows, and DisclosedRows properties need to be updated after dynamic page changes
https://bugs.webkit.org/show_bug.cgi?id=238844

Reviewed by Chris Fleizach.

Source/WebCore:

Before this patch, we never updated these properties after
initializing isolated objects, so they become inaccurate
when content / rows were added or removed.

Test: accessibility/mac/tree-properties-update-after-dynamic-change.html

* accessibility/AccessibilityObject.cpp:
(WebCore::AccessibilityObject::ariaTreeItemContent):
Make this function return a value instead of by out-parameter.
* accessibility/AccessibilityObject.h:
* accessibility/AccessibilityObjectInterface.h:
* accessibility/isolatedtree/AXIsolatedObject.cpp:
(WebCore::AXIsolatedObject::initializeAttributeData):
* accessibility/isolatedtree/AXIsolatedObject.h:
* accessibility/isolatedtree/AXIsolatedTree.cpp:
(WebCore::AXIsolatedTree::updateNodeProperty):
Handle updates to AXPropertyName::ARIATreeItemContent, AXPropertyName::ARIATreeRows, and
AXPropertyName::DisclosedRows. Also, updateNodeProperty now
takes an `AXCoreObject&` instead of `const AXCoreObject&`
since calling ariaTreeItemContent(), ariaTreeRows(), and disclosedRows() is inherently not const.
(WebCore::AXIsolatedTree::updateChildren):
If the object being updated is a treeitem, also update AXPropertyName::ARIATreeItemContent
and AXPropertyName::DisclosedRows. And if the object has a tree role ancestor, update
AXPropertyName::ARIATreeRows for that ancestor.
* accessibility/isolatedtree/AXIsolatedTree.h:
* accessibility/mac/WebAccessibilityObjectWrapperMac.mm:
(-[WebAccessibilityObjectWrapper accessibilityAttributeValue:]):

LayoutTests:

* accessibility/mac/tree-properties-update-after-dynamic-change-expected.txt: Added.
* accessibility/mac/tree-properties-update-after-dynamic-change.html: Added.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@292564 268f45cc-cd09-0410-ab3c-d52691b4dbfc