AX: Relations updates thrash between dirty and clean when multiple de…

…ferred id attribute changes are processed

https://bugs.webkit.org/show_bug.cgi?id=260370
rdar://problem/114052085

Reviewed by Andres Gonzalez.

In AXObjectCache::handleAttributeChange, any change to the `id`
attribute causes AXObjectCache::m_relationsNeedUpdate to become true.

This is problematic when `m_deferredAttributeChange` contains multiple
`id` attribute changes, as we thrash between setting m_relationsNeedUpdate to true,
immediately resetting it to false as a result of an arbitrary` parentObject` call,
and then re-dirtying it with the next id attribute change.

With this patch (authored by Andres Gonzalez), we only update relations
once, even when a group of id attribute changes are processed.

* Source/WebCore/accessibility/AXObjectCache.cpp:
(WebCore::AXObjectCache::performDeferredCacheUpdate):
(WebCore::AXObjectCache::relationsNeedUpdate):
* Source/WebCore/accessibility/AXObjectCache.h:

Canonical link: https://commits.webkit.org/267190@main

Source/WebCore/accessibility/AXObjectCache.cpp

@@ -2298,6 +2298,8 @@ void AXObjectCache::deferAttributeChangeIfNeeded(Element* element, const Qualifi
     }
     RefPtr protectedElement { element };
     handleAttributeChange(protectedElement.get(), attrName, oldValue, newValue);
+    if (attrName == idAttr)
+        relationsNeedUpdate(true);
 }
 
 bool AXObjectCache::shouldProcessAttributeChange(Element* element, const QualifiedName& attrName)
@@ -2373,7 +2375,6 @@ void AXObjectCache::handleAttributeChange(Element* element, const QualifiedName&
     else if (attrName == hrefAttr)
         updateIsolatedTree(get(element), AXURLChanged);
     else if (attrName == idAttr) {
-        relationsNeedUpdate(true);
 #if !LOG_DISABLED
         updateIsolatedTree(get(element), AXIdAttributeChanged);
 #endif
@@ -3854,9 +3855,15 @@ void AXObjectCache::performDeferredCacheUpdate()
     m_deferredTextFormControlValue.clear();
 
     AXLOGDeferredCollection("AttributeChange"_s, m_deferredAttributeChange);
-    for (const auto& attributeChange : m_deferredAttributeChange)
+    bool idAttributeChanged = false;
+    for (const auto& attributeChange : m_deferredAttributeChange) {
         handleAttributeChange(attributeChange.element.get(), attributeChange.attrName, attributeChange.oldValue, attributeChange.newValue);
+        if (attributeChange.attrName == idAttr)
+            idAttributeChanged = true;
+    }
     m_deferredAttributeChange.clear();
+    if (idAttributeChanged)
+        relationsNeedUpdate(true);
 
     if (m_deferredFocusedNodeChange) {
         AXLOG(makeString(