Implement the inert attribute

third_party/WebKit/Source/modules/accessibility/AXObject.cpp

Index: third_party/WebKit/Source/modules/accessibility/AXObject.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/AXObject.cpp b/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
index 2cae448cea5924e6a4d2b86e6dc2643618255bf7..2062c34ec7fa3c9b260026302b799ef51dec2ca6 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXObject.cpp
@@ -533,7 +533,24 @@ bool AXObject::IsClickable() const {
   }
 }
 
-bool AXObject::AccessibilityIsIgnored() const {
+bool AXObject::AccessibilityIsIgnored() {
+  Node* node = GetNode();
+  if (!node) {
+    AXObject* parent = this->ParentObject();
+    while (!node && parent) {
+      node = parent->GetNode();
+      parent = parent->ParentObject();
+    }
+  }
+
+  if (node)
+    node->UpdateDistribution();
+
+  // TODO(aboxhall): Instead of this, propagate inert down through frames
+  Document* document = GetDocument();
+  if (document && document->LocalOwner())
+    document->LocalOwner()->UpdateDistribution();

[esprehn, 2017/05/12 21:16:54]

Why are you updating the distribution of the parent iframe? This doesn't go all
the way up, so I suspect it still doesn't work if you're multiple levels down in
distributed frames.

[aboxhall, 2017/05/18 01:30:49]

It crashes (DCHECK fails) without this in certain situations. I should probably
walk all the way up in case there are crashes we're missing in tests.

+
   UpdateCachedAttributeValuesIfNeeded();
   return cached_is_ignored_;
 }
@@ -615,10 +632,15 @@ bool AXObject::ComputeIsInertOrAriaHidden(
             ignored_reasons->push_back(
                 IgnoredReason(kAXActiveModalDialog, dialog_object));
           else
-            ignored_reasons->push_back(IgnoredReason(kAXInert));
+            ignored_reasons->push_back(IgnoredReason(kAXInertElement));
         } else {
-          // TODO(aboxhall): handle inert attribute if it eventuates
-          ignored_reasons->push_back(IgnoredReason(kAXInert));
+          const AXObject* inert_root_el = InertRoot();
+          if (inert_root_el == this) {
+            ignored_reasons->push_back(IgnoredReason(kAXInertElement));
+          } else {
+            ignored_reasons->push_back(
+                IgnoredReason(kAXInertSubtree, inert_root_el));
+          }
         }
       }
       return true;
@@ -635,11 +657,12 @@ bool AXObject::ComputeIsInertOrAriaHidden(
   const AXObject* hidden_root = AriaHiddenRoot();
   if (hidden_root) {
     if (ignored_reasons) {
-      if (hidden_root == this)
-        ignored_reasons->push_back(IgnoredReason(kAXAriaHidden));
-      else
+      if (hidden_root == this) {
+        ignored_reasons->push_back(IgnoredReason(kAXAriaHiddenElement));
+      } else {
         ignored_reasons->push_back(
-            IgnoredReason(kAXAriaHiddenRoot, hidden_root));
+            IgnoredReason(kAXAriaHiddenSubtree, hidden_root));
+      }
     }
     return true;
   }
@@ -672,6 +695,26 @@ const AXObject* AXObject::AriaHiddenRoot() const {
   return 0;
 }
 
+const AXObject* AXObject::InertRoot() const {
+  const AXObject* object = this;
+  if (!RuntimeEnabledFeatures::inertAttributeEnabled())
+    return 0;
+
+  while (object && !object->IsAXNodeObject())
+    object = object->ParentObject();
+  Node* node = object->GetNode();
+  Element* element = node->IsElementNode()
+                         ? ToElement(node)
+                         : FlatTreeTraversal::ParentElement(*node);

[esprehn, 2017/05/12 21:16:54]

You could add FlatTreeTraversal::ParentElementOrSelf(node) and use it here and
elsewhere.

[aboxhall, 2017/05/18 01:30:49]

This actually doesn't seem to be a super common case, so I'll leave it as-is.

+  while (element) {
+    if (element->hasAttribute(inertAttr))
+      return AxObjectCache().GetOrCreate(element);
+    element = FlatTreeTraversal::ParentElement(*element);
+  }
+
+  return 0;
+}
+
 bool AXObject::IsDescendantOfDisabledNode() const {
   UpdateCachedAttributeValuesIfNeeded();
   return cached_is_descendant_of_disabled_node_;
@@ -1216,11 +1259,7 @@ void AXObject::ClearChildren() {
 }
 
 Document* AXObject::GetDocument() const {
-  FrameView* frame_view = DocumentFrameView();
-  if (!frame_view)
-    return 0;
-
-  return frame_view->GetFrame().GetDocument();
+  return &(AxObjectCache().GetDocument());
 }
 
 FrameView* AXObject::DocumentFrameView() const {