Simplify last known ignored code

- Remove 2 member variables and 2 methods from AXObject, which were used
so that AXObject could calculate whether ignored changed.
- Remove repetitive code from AXObjectCacheImpl, whenever an
AXObject is created.

Bug: None
Change-Id: Iad38383819dd1d165169fd302a717f3e2bacb2b9
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2383813
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Cr-Commit-Position: refs/heads/master@{#803250}

third_party/blink/renderer/modules/accessibility/ax_menu_list.cc

@@ -75,11 +75,7 @@ void AXMenuList::AddChildren() {
 
   AXObjectCacheImpl& cache = AXObjectCache();
 
-  AXObject* popup = cache.GetOrCreate(ax::mojom::Role::kMenuListPopup);
-  if (!popup)
-    return;
-
-  To<AXMockObject>(popup)->SetParent(this);
+  AXObject* popup = cache.Create(ax::mojom::blink::Role::kMenuListPopup, this);
   if (!popup->AccessibilityIsIncludedInTree()) {
     cache.Remove(popup->AXObjectID());
     return;

third_party/blink/renderer/modules/accessibility/ax_object.cc

@@ -520,8 +520,6 @@ AXObject::AXObject(AXObjectCacheImpl& ax_object_cache)
       have_children_(false),
       role_(ax::mojom::blink::Role::kUnknown),
       aria_role_(ax::mojom::blink::Role::kUnknown),
-      last_known_is_ignored_value_(kDefaultBehavior),
-      last_known_is_ignored_but_included_in_tree_value_(kDefaultBehavior),
       explicit_container_id_(0),
       parent_(nullptr),
       last_modification_count_(-1),
@@ -546,6 +544,7 @@ AXObject::~AXObject() {
 
 void AXObject::Init() {
   role_ = DetermineAccessibilityRole();
+  UpdateCachedAttributeValuesIfNeeded();
 }
 
 void AXObject::Detach() {
@@ -1231,9 +1230,22 @@ void AXObject::UpdateCachedAttributeValuesIfNeeded() const {
   cached_is_descendant_of_disabled_node_ = !!DisabledAncestor();
   cached_has_inherited_presentational_role_ =
       !!InheritsPresentationalRoleFrom();
-  cached_is_ignored_ = ComputeAccessibilityIsIgnored();
-  cached_is_ignored_but_included_in_tree_ =
-      cached_is_ignored_ && ComputeAccessibilityIsIgnoredButIncludedInTree();
+  bool is_ignored = ComputeAccessibilityIsIgnored();
+  bool is_ignored_but_included_in_tree =
+      is_ignored && ComputeAccessibilityIsIgnoredButIncludedInTree();
+  bool ignored_states_changed = false;
+  if (parent_) {
+    // Do not compute ignored changed if no parent, because this is the first
+    // time the object is being initialized, and because there are no
+    // ancestors to call ChildrenChanged() on anyway.
+    if (is_ignored != cached_is_ignored_ ||
+        is_ignored_but_included_in_tree !=
+            cached_is_ignored_but_included_in_tree_) {
+      ignored_states_changed = true;
+    }
+  }
+  cached_is_ignored_ = is_ignored;
+  cached_is_ignored_but_included_in_tree_ = is_ignored_but_included_in_tree;
   cached_is_editable_root_ = ComputeIsEditableRoot();
   // Compute live region root, which can be from any ARIA live value, including
   // "off", or from an automatic ARIA live value, e.g. from role="status".
@@ -1247,21 +1259,6 @@ void AXObject::UpdateCachedAttributeValuesIfNeeded() const {
   cached_aria_column_index_ = ComputeAriaColumnIndex();
   cached_aria_row_index_ = ComputeAriaRowIndex();
 
-  bool ignored_states_changed = false;
-  if (cached_is_ignored_ != LastKnownIsIgnoredValue()) {
-    last_known_is_ignored_value_ =
-        cached_is_ignored_ ? kIgnoreObject : kIncludeObject;
-    ignored_states_changed = true;
-  }
-
-  if (cached_is_ignored_but_included_in_tree_ !=
-      LastKnownIsIgnoredButIncludedInTreeValue()) {
-    last_known_is_ignored_but_included_in_tree_value_ =
-        cached_is_ignored_but_included_in_tree_ ? kIncludeObject
-                                                : kIgnoreObject;
-    ignored_states_changed = true;
-  }
-
   if (ignored_states_changed) {
     if (AXObject* parent = ParentObjectIfExists())
       parent->ChildrenChanged();
@@ -1620,32 +1617,11 @@ const AXObject* AXObject::DatetimeAncestor(int max_levels_to_check) const {
 }
 
 bool AXObject::LastKnownIsIgnoredValue() const {
-  if (last_known_is_ignored_value_ == kDefaultBehavior) {
-    last_known_is_ignored_value_ =
-        AccessibilityIsIgnored() ? kIgnoreObject : kIncludeObject;
-  }
-
-  return last_known_is_ignored_value_ == kIgnoreObject;
-}
-
-void AXObject::SetLastKnownIsIgnoredValue(bool is_ignored) {
-  last_known_is_ignored_value_ = is_ignored ? kIgnoreObject : kIncludeObject;
+  return cached_is_ignored_;
 }
 
 bool AXObject::LastKnownIsIgnoredButIncludedInTreeValue() const {
-  if (last_known_is_ignored_but_included_in_tree_value_ == kDefaultBehavior) {
-    last_known_is_ignored_but_included_in_tree_value_ =
-        AccessibilityIsIgnoredButIncludedInTree() ? kIncludeObject
-                                                  : kIgnoreObject;
-  }
-
-  return last_known_is_ignored_but_included_in_tree_value_ == kIncludeObject;
-}
-
-void AXObject::SetLastKnownIsIgnoredButIncludedInTreeValue(
-    bool is_ignored_but_included_in_tree) {
-  last_known_is_ignored_but_included_in_tree_value_ =
-      is_ignored_but_included_in_tree ? kIncludeObject : kIgnoreObject;
+  return cached_is_ignored_but_included_in_tree_;
 }
 
 bool AXObject::HasInheritedPresentationalRole() const {

third_party/blink/renderer/modules/accessibility/ax_object.h

@@ -540,9 +540,7 @@ class MODULES_EXPORT AXObject : public GarbageCollected<AXObject> {
   const AXObject* DatetimeAncestor(int max_levels_to_check = 3) const;
   const AXObject* DisabledAncestor() const;
   bool LastKnownIsIgnoredValue() const;
-  void SetLastKnownIsIgnoredValue(bool);
   bool LastKnownIsIgnoredButIncludedInTreeValue() const;
-  void SetLastKnownIsIgnoredButIncludedInTreeValue(bool);
   bool HasInheritedPresentationalRole() const;
   bool IsPresentationalChild() const;
   bool CanBeActiveDescendant() const;
@@ -1196,8 +1194,6 @@ class MODULES_EXPORT AXObject : public GarbageCollected<AXObject> {
   mutable bool have_children_;
   ax::mojom::blink::Role role_;
   ax::mojom::blink::Role aria_role_;
-  mutable AXObjectInclusion last_known_is_ignored_value_;
-  mutable AXObjectInclusion last_known_is_ignored_but_included_in_tree_value_;
   LayoutRect explicit_element_rect_;
   AXID explicit_container_id_;
 

third_party/blink/renderer/modules/accessibility/ax_object_cache_impl.cc

@@ -356,9 +356,6 @@ AXObject* AXObjectCacheImpl::Get(const Node* node) {
     new_obj->SetAXObjectID(node_id);
     objects_.Set(node_id, new_obj);
     new_obj->Init();
-    new_obj->SetLastKnownIsIgnoredValue(new_obj->AccessibilityIsIgnored());
-    new_obj->SetLastKnownIsIgnoredButIncludedInTreeValue(
-        new_obj->AccessibilityIsIgnoredButIncludedInTree());
     return new_obj;
   }
 
@@ -540,9 +537,6 @@ AXObject* AXObjectCacheImpl::GetOrCreate(Node* node) {
   DCHECK(!HashTraits<AXID>::IsDeletedValue(ax_id));
   node_object_mapping_.Set(node, ax_id);
   new_obj->Init();
-  new_obj->SetLastKnownIsIgnoredValue(new_obj->AccessibilityIsIgnored());
-  new_obj->SetLastKnownIsIgnoredButIncludedInTreeValue(
-      new_obj->AccessibilityIsIgnoredButIncludedInTree());
   MaybeNewRelationTarget(node, new_obj);
 
   return new_obj;
@@ -592,9 +586,6 @@ AXObject* AXObjectCacheImpl::GetOrCreate(LayoutObject* layout_object) {
 
   layout_object_mapping_.Set(layout_object, axid);
   new_obj->Init();
-  new_obj->SetLastKnownIsIgnoredValue(new_obj->AccessibilityIsIgnored());
-  new_obj->SetLastKnownIsIgnoredButIncludedInTreeValue(
-      new_obj->AccessibilityIsIgnoredButIncludedInTree());
   if (node && node->GetLayoutObject() == layout_object) {
     AXID prev_axid = node_object_mapping_.at(node);
     if (prev_axid != 0 && prev_axid != axid) {
@@ -624,20 +615,18 @@ AXObject* AXObjectCacheImpl::GetOrCreate(
 
   inline_text_box_object_mapping_.Set(inline_text_box, axid);
   new_obj->Init();
-  new_obj->SetLastKnownIsIgnoredValue(new_obj->AccessibilityIsIgnored());
-  new_obj->SetLastKnownIsIgnoredButIncludedInTreeValue(
-      new_obj->AccessibilityIsIgnoredButIncludedInTree());
   return new_obj;
 }
 
-AXObject* AXObjectCacheImpl::GetOrCreate(ax::mojom::blink::Role role) {
+AXObject* AXObjectCacheImpl::Create(ax::mojom::blink::Role role,
+                                    AXObject* parent) {
   AXObject* obj = nullptr;
 
   switch (role) {
-    case ax::mojom::Role::kSliderThumb:
+    case ax::mojom::blink::Role::kSliderThumb:
       obj = MakeGarbageCollected<AXSliderThumb>(*this);
       break;
-    case ax::mojom::Role::kMenuListPopup:
+    case ax::mojom::blink::Role::kMenuListPopup:
       DCHECK(use_ax_menu_list_);
       obj = MakeGarbageCollected<AXMenuListPopup>(*this);
       break;
@@ -649,6 +638,7 @@ AXObject* AXObjectCacheImpl::GetOrCreate(ax::mojom::blink::Role role) {
     return nullptr;
 
   GetOrCreateAXID(obj);
+  obj->SetParent(parent);
 
   obj->Init();
   return obj;

third_party/blink/renderer/modules/accessibility/ax_object_cache_impl.h

@@ -175,8 +175,9 @@ class MODULES_EXPORT AXObjectCacheImpl
   AXObject* ObjectFromAXID(AXID id) const { return objects_.at(id); }
   AXObject* Root();
 
-  // used for objects without backing elements
-  AXObject* GetOrCreate(ax::mojom::blink::Role);
+  // Used for objects without backing DOM nodes, layout objects, etc.
+  AXObject* Create(ax::mojom::blink::Role, AXObject* parent);
+
   AXObject* GetOrCreate(AccessibleNode*);
   AXObject* GetOrCreate(LayoutObject*) override;
   AXObject* GetOrCreate(const Node*);

third_party/blink/renderer/modules/accessibility/ax_slider.cc

@@ -83,9 +83,7 @@ void AXSlider::AddChildren() {
 
   AXObjectCacheImpl& cache = AXObjectCache();
 
-  AXSliderThumb* thumb = static_cast<AXSliderThumb*>(
-      cache.GetOrCreate(ax::mojom::Role::kSliderThumb));
-  thumb->SetParent(this);
+  AXObject* thumb = cache.Create(ax::mojom::blink::Role::kSliderThumb, this);
 
   // Before actually adding the value indicator to the hierarchy,
   // allow the platform to make a final decision about it.