An unknown role is considered a bug, should never occur

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

Index: third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp
diff --git a/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp b/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp
index 803370747873c15192e64a72b909aa4aea3faaa8..e621f714a43e0c01025cc20d210fe94cc938ccda 100644
--- a/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp
+++ b/third_party/WebKit/Source/modules/accessibility/AXLayoutObject.cpp
@@ -292,20 +292,11 @@ AccessibilityRole AXLayoutObject::DetermineAccessibilityRole() {
     return aria_role_;
 
   AccessibilityRole role = NativeAccessibilityRoleIgnoringAria();
-  if (role != kUnknownRole)
-    return role;
-
-  // These are layout containers added by blink
-  if (layout_object_->IsLayoutBlockFlow())
-    return kGenericContainerRole;
-
-  // If the element does not have role, but it has ARIA attributes or is an
-  // in-page link target, accessibility should fallback to exposing it as a
-  // generic container.
-  if (IsInPageLinkTarget() || SupportsARIAAttributes())
-    return kGenericContainerRole;
-
-  return kUnknownRole;
+  // Anything that needs to still be exposed but doesn't have a more specific
+  // role should be considered a generic container. Examples are
+  // layout blocks with no node, in-page link targets, and plain elements
+  // such as a <span> with ARIA markup.
+  return role == kUnknownRole ? kGenericContainerRole : role;
 }
 
 void AXLayoutObject::Init() {