From d7291370c5dfcf0aed4818c07d1836ed55e0a336 Mon Sep 17 00:00:00 2001
From: Tyler Wilcock <tyler_w@apple.com>
Date: Sat, 17 Sep 2022 20:00:10 -0700
Subject: [PATCH] AX: AccessibilityNodeObject never resets m_childrenDirty to
 false https://bugs.webkit.org/show_bug.cgi?id=245322 rdar://problem/100073372

Reviewed by Chris Fleizach.

In https://bugs.webkit.org/show_bug.cgi?id=245212, we moved these
methods from AccessibilityRenderObject to AccessibilityNodeObject:

  - updateChildrenIfNecessary
  - setNeedsToUpdateChildren
  - needsToUpdateChildren
  - setNeedsToUpdateSubtree

But crucially, we did not move the implementation of clearChildren,
which is what resets m_childrenDirty to false when necessary, causing a
performance issue (not a correctness issue) for these objects.

* Source/WebCore/accessibility/AccessibilityNodeObject.cpp:
(WebCore::AccessibilityNodeObject::clearChildren):
* Source/WebCore/accessibility/AccessibilityNodeObject.h:
* Source/WebCore/accessibility/AccessibilityRenderObject.cpp:
(WebCore::AccessibilityRenderObject::clearChildren): Deleted.
* Source/WebCore/accessibility/AccessibilityRenderObject.h:

Canonical link: https://commits.webkit.org/254600@main
---
 Source/WebCore/accessibility/AccessibilityNodeObject.cpp   | 6 ++++++
 Source/WebCore/accessibility/AccessibilityNodeObject.h     | 1 +
 Source/WebCore/accessibility/AccessibilityRenderObject.cpp | 6 ------
 Source/WebCore/accessibility/AccessibilityRenderObject.h   | 2 --
 4 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/Source/WebCore/accessibility/AccessibilityNodeObject.cpp b/Source/WebCore/accessibility/AccessibilityNodeObject.cpp
index cb281fac8bcd..6e6503c81575 100644
--- a/Source/WebCore/accessibility/AccessibilityNodeObject.cpp
+++ b/Source/WebCore/accessibility/AccessibilityNodeObject.cpp
@@ -455,6 +455,12 @@ void AccessibilityNodeObject::updateChildrenIfNecessary()
     AccessibilityObject::updateChildrenIfNecessary();
 }
 
+void AccessibilityNodeObject::clearChildren()
+{
+    AccessibilityObject::clearChildren();
+    m_childrenDirty = false;
+}
+
 void AccessibilityNodeObject::addChildren()
 {
     // If the need to add more children in addition to existing children arises, 
diff --git a/Source/WebCore/accessibility/AccessibilityNodeObject.h b/Source/WebCore/accessibility/AccessibilityNodeObject.h
index 38f1cc468d89..c2013bf78a52 100644
--- a/Source/WebCore/accessibility/AccessibilityNodeObject.h
+++ b/Source/WebCore/accessibility/AccessibilityNodeObject.h
@@ -164,6 +164,7 @@ class AccessibilityNodeObject : public AccessibilityObject {
     AccessibilityRole remapAriaRoleDueToParent(AccessibilityRole) const;
 
     void addChildren() override;
+    void clearChildren() override;
     void updateChildrenIfNecessary() override;
     bool canHaveChildren() const override;
     bool isDescendantOfBarrenParent() const override;
diff --git a/Source/WebCore/accessibility/AccessibilityRenderObject.cpp b/Source/WebCore/accessibility/AccessibilityRenderObject.cpp
index 522becc0f0ad..68ba1a70e56d 100644
--- a/Source/WebCore/accessibility/AccessibilityRenderObject.cpp
+++ b/Source/WebCore/accessibility/AccessibilityRenderObject.cpp
@@ -2902,12 +2902,6 @@ bool AccessibilityRenderObject::canSetTextRangeAttributes() const
     return isTextControl();
 }
 
-void AccessibilityRenderObject::clearChildren()
-{
-    AccessibilityObject::clearChildren();
-    m_childrenDirty = false;
-}
-
 void AccessibilityRenderObject::addImageMapChildren()
 {
     RenderBoxModelObject* cssBox = renderBoxModelObject();
diff --git a/Source/WebCore/accessibility/AccessibilityRenderObject.h b/Source/WebCore/accessibility/AccessibilityRenderObject.h
index c977948d6a6a..78f9b5d69076 100644
--- a/Source/WebCore/accessibility/AccessibilityRenderObject.h
+++ b/Source/WebCore/accessibility/AccessibilityRenderObject.h
@@ -133,8 +133,6 @@ class AccessibilityRenderObject : public AccessibilityNodeObject {
     AccessibilityChildrenVector documentLinks() override;
     FrameView* documentFrameView() const override;
 
-    void clearChildren() override;
-    
     void setFocused(bool) override;
     void setSelectedTextRange(const PlainTextRange&) override;
     bool setValue(const String&) override;