Expose blink accessibility objects hidden via display:none on ancestor

Accessible objects styled with display:none are supposed to be exposed
when they have an id. However, this currently only works if the
display:none style targets the element directly. It also needs to work
if the display:none targets an ancestor.

This is also a necessary precursor to
https://chromium-review.googlesource.com/c/chromium/src/+/2090736

Bug: 651614
Change-Id: I789cda53f303ddfc3304f6109102b71090619aa2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2095880
Commit-Queue: Aaron Leventhal <aleventhal@chromium.org>
Reviewed-by: Dominic Mazzoni <dmazzoni@chromium.org>
Reviewed-by: Adam Ettenberger <Adam.Ettenberger@microsoft.com>
Cr-Commit-Position: refs/heads/master@{#751439}

content/test/data/accessibility/aria/aria-hidden-expected-android.txt

 android.webkit.WebView focusable focused scrollable
 ++android.view.View name='blockDisplay'
 ++android.view.View name='blockDisplay Hiddenfalse'
-++android.view.View
+++android.view.View invisible
 ++android.view.View focusable invisible name='blockDisplay Hiddentruefocusable'
\ No newline at end of file

content/test/data/accessibility/aria/aria-hidden-expected-auralinux.txt

@@ -3,5 +3,5 @@
 ++++[static] name='blockDisplay'
 ++[section]
 ++++[static] name='blockDisplay Hiddenfalse'
-++[section]
+++[section] hidden:true
 ++[section] name='blockDisplay Hiddentruefocusable' hidden:true
\ No newline at end of file

content/test/data/accessibility/aria/aria-hidden-expected-blink.txt

@@ -10,6 +10,6 @@ rootWebArea isLineBreakingObject=true
 ++++genericContainer isLineBreakingObject=true
 ++++++staticText name='blockDisplay Hiddenfalse'
 ++++++++inlineTextBox name='blockDisplay Hiddenfalse'
-++++genericContainer
+++++genericContainer invisible
 ++++genericContainer invisible name='blockDisplay Hiddentruefocusable' isLineBreakingObject=true
 ++++++staticText ignored invisible name='blockDisplay Hiddentruefocusable'
\ No newline at end of file

content/test/data/accessibility/aria/aria-hidden-expected-win.txt

@@ -3,5 +3,5 @@ ROLE_SYSTEM_DOCUMENT READONLY FOCUSABLE
 ++++ROLE_SYSTEM_STATICTEXT name='blockDisplay'
 ++IA2_ROLE_SECTION
 ++++ROLE_SYSTEM_STATICTEXT name='blockDisplay Hiddenfalse'
-++IA2_ROLE_SECTION
+++IA2_ROLE_SECTION INVISIBLE hidden:true
 ++IA2_ROLE_SECTION name='blockDisplay Hiddentruefocusable' INVISIBLE FOCUSABLE hidden:true
\ No newline at end of file

content/test/data/accessibility/css/display-to-none-expected-blink.txt

@@ -5,6 +5,7 @@ rootWebArea
 ++++++++staticText name='Cats'
 ++++++++++inlineTextBox name='Cats'
 ++++++genericContainer ignored invisible name='checkbox'
+++++++++checkBox ignored invisible name='checkbox' checkedState=false
 ++++++genericContainer
 ++++++++staticText name='done'
 ++++++++++inlineTextBox name='done'

content/test/data/accessibility/css/display-to-none.html

@@ -4,7 +4,7 @@
 <div>
   <div>Cats</div>
   <div id="none">
-      <input type="checkbox" aria-label="checkbox">
+      <input type="checkbox" aria-label="checkbox" id="cbox1">
   </div>
   <div><code>pending</code></div>
 </div>

content/test/data/accessibility/event/menu-opened-closed-expected-uia-win.txt

 #<skip -- crbug.com/1062697>
 AriaProperties changed on role=menu, name=menu
+AriaProperties changed on role=menuitem, name=submenu1
+AriaProperties changed on role=menuitem, name=submenu2
 MenuOpened on role=menu, name=menu
-MenuOpened on role=region
 === Start Continuation ===
 AriaProperties changed on role=menu
+AriaProperties changed on role=menuitem, name=option
 MenuOpened on role=menu
-MenuOpened on role=region
 === Start Continuation ===
 MenuClosed 
 MenuClosed 

content/test/data/accessibility/html/open-modal-expected-blink.txt

@@ -3,14 +3,15 @@ rootWebArea
 ++++staticText name='some text'
 ++++++inlineTextBox name='some text'
 ++++genericContainer ignored
+++++++genericContainer ignored invisible
 === Start Continuation ===
 rootWebArea
 ++genericContainer ignored invisible
 ++++genericContainer ignored invisible
 ++++++dialog
-++++++++genericContainer name='Dialog Text'
-++++++++++staticText name='Dialog Text'
-++++++++++++inlineTextBox name='Dialog Text'
+++++++++genericContainer name='Some Text'
+++++++++++staticText name='Some Text'
+++++++++++++inlineTextBox name='Some Text'
 === Start Continuation ===
 rootWebArea
 ++genericContainer ignored invisible

content/test/data/accessibility/html/open-modal.html

@@ -11,7 +11,7 @@ their parent. crbug: 996992
 <span>some text</span>
 <div>
   <dialog>
-    <div id="dialog-text" tabindex="0">Dialog Text</div>
+    <div id="dialog-text" tabindex="0">Some Text</div>
   </dialog>
 </div>
 
@@ -19,7 +19,7 @@ their parent. crbug: 996992
 <script>
   function open_modal() {
     document.querySelector("dialog").showModal();
-    return "Dialog Text";
+    return "dialog";
   }
   function remove_span() {
     // Cause the root to be updated.

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

@@ -1066,7 +1066,7 @@ bool AXObject::ComputeIsInertOrAriaHidden(
 }
 
 bool AXObject::IsVisible() const {
-  return !IsInertOrAriaHidden() && !IsHiddenForTextAlternativeCalculation();
+  return !IsInertOrAriaHidden() && !IsHiddenViaStyle();
 }
 
 bool AXObject::IsDescendantOfLeafNode() const {
@@ -1242,7 +1242,7 @@ bool AXObject::ComputeAccessibilityIsIgnoredButIncludedInTree() const {
   if (RuntimeEnabledFeatures::AccessibilityExposeDisplayNoneEnabled()) {
     if (Element* element = GetElement()) {
       if (element->FastHasAttribute(html_names::kIdAttr) &&
-          IsHiddenForTextAlternativeCalculation()) {
+          IsHiddenViaStyle()) {
         return true;
       }
     }
@@ -1636,6 +1636,33 @@ String AXObject::RecursiveTextAlternative(const AXObject& ax_obj,
                                 name_from, nullptr, nullptr);
 }
 
+bool AXObject::IsHiddenViaStyle() const {
+  if (GetLayoutObject())
+    return GetLayoutObject()->Style()->Visibility() != EVisibility::kVisible;
+  if (Node* node = GetNode()) {
+    if (node->isConnected()) {
+      bool is_first_loop = true;
+      auto* element = DynamicTo<Element>(node);
+      while (element && !element->GetLayoutObject()) {
+        const ComputedStyle* style = element->EnsureComputedStyle();
+        if (is_first_loop && style->Visibility() != EVisibility::kVisible)
+          return true;
+        // CSS Display:
+        // - does not inherit
+        // - display: none affects entire subtrees regardless of descendants
+        //   attempting to override it
+        // - causes elements to have no associated layout object
+        // Therefore, check each consecutive parent without a layout object.
+        if (style->Display() == EDisplay::kNone)
+          return true;
+        element = element->parentElement();
+        is_first_loop = false;
+      }
+    }
+  }
+  return false;
+}
+
 bool AXObject::IsHiddenForTextAlternativeCalculation() const {
   if (AOMPropertyOrARIAAttributeIsFalse(AOMBooleanProperty::kHidden))
     return false;

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

@@ -1147,6 +1147,7 @@ class MODULES_EXPORT AXObject : public GarbageCollected<AXObject> {
   bool HasInternalsAttribute(Element&, const QualifiedName&) const;
   const AtomicString& GetInternalsAttribute(Element&,
                                             const QualifiedName&) const;
+  bool IsHiddenViaStyle() const;
 
   static unsigned number_of_live_ax_objects_;