AX: AXObjectCache::updateIsolatedTree may cause the update of depende…

…nt properties for the same object multiple times unnecessarily.

https://bugs.webkit.org/show_bug.cgi?id=267599
<rdar://problem/121065998>

Reviewed by Tyler Wilcock.

AXObjectCache::updateIsolatedTree calls AXIsolatedTree::updateDependentProperties twice unnecessarily in the following scenario:
1. The passed Vector of { object, notification } contains two LabelChanged notifications.
2. There is another notification in between the two label changes that causes an updateNode.
This patch fixes this problem and replaces the struct UpdatedFields that was being used before to prevent duplication of node updates with an OptionSet. This should be somewhat more efficient and less errorprone than the existing implementation.

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

Canonical link: https://commits.webkit.org/273106@main

Source/WebCore/accessibility/AXObjectCache.cpp

@@ -4167,16 +4167,33 @@ void AXObjectCache::updateIsolatedTree(const Vector<std::pair<RefPtr<Accessibili
         return;
     }
 
-    struct UpdatedFields {
-        bool children { false };
-        bool node { false };
-        bool dependentProperties { false };
+    enum class Field : uint8_t {
+        Children = 1 << 0,
+        DependentProperties = 1 << 1,
+        Node = 1 << 2,
+    };
+    HashMap<AXID, OptionSet<Field>> updatedObjects;
+    auto updateChildren = [&] (RefPtr<AccessibilityObject> axObject) {
+        auto updatedFields = updatedObjects.get(axObject->objectID());
+        if (!updatedFields.contains(Field::Children)) {
+            updatedFields.add(Field::Children);
+            updatedObjects.set(axObject->objectID(), updatedFields);
+            tree->queueNodeUpdate(*axObject, NodeUpdateOptions::childrenUpdate());
+        }
+    };
+    auto updateDependentProperties = [&] (RefPtr<AccessibilityObject> axObject) {
+        auto updatedFields = updatedObjects.get(axObject->objectID());
+        if (!updatedFields.contains(Field::DependentProperties)) {
+            updatedFields.add(Field::DependentProperties);
+            updatedObjects.set(axObject->objectID(), updatedFields);
+            tree->updateDependentProperties(*axObject);
+        }
     };
-    HashMap<AXID, UpdatedFields> updatedObjects;
     auto updateNode = [&] (RefPtr<AccessibilityObject> axObject) {
         auto updatedFields = updatedObjects.get(axObject->objectID());
-        if (!updatedFields.node) {
-            updatedObjects.set(axObject->objectID(), UpdatedFields { updatedFields.children, true });
+        if (!updatedFields.contains(Field::Node)) {
+            updatedFields.add(Field::Node);
+            updatedObjects.set(axObject->objectID(), updatedFields);
             tree->queueNodeUpdate(*axObject, NodeUpdateOptions::nodeUpdate());
         }
     };
@@ -4332,27 +4349,17 @@ void AXObjectCache::updateIsolatedTree(const Vector<std::pair<RefPtr<Accessibili
             break;
         case AXLabelChanged: {
             updateNode(notification.first);
-
-            auto updatedFields = updatedObjects.get(notification.first->objectID());
-            if (!updatedFields.dependentProperties) {
-                updatedObjects.set(notification.first->objectID(), UpdatedFields { updatedFields.children, updatedFields.node, true });
-                tree->updateDependentProperties(*notification.first);
-            }
+            updateDependentProperties(notification.first);
             break;
         }
         case AXLanguageChanged:
         case AXRowCountChanged:
             updateNode(notification.first);
             FALLTHROUGH;
         case AXRowCollapsed:
-        case AXRowExpanded: {
-            auto updatedFields = updatedObjects.get(notification.first->objectID());
-            if (!updatedFields.children) {
-                updatedObjects.set(notification.first->objectID(), UpdatedFields { true, updatedFields.node });
-                tree->queueNodeUpdate(*notification.first, NodeUpdateOptions::childrenUpdate());
-            }
+        case AXRowExpanded:
+            updateChildren(notification.first);
             break;
-        }
         default:
             break;
         }