Selection follows focus/activedescendant in single selection containers

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

 /*
  * Copyright (C) 2012, Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 1276 matching lines @@
 
   if (IsTextControl() && !IsNativeTextControl())
     return true;
 
   // Any node could be contenteditable, so isReadOnly should be relied upon
   // for this information for all elements.
   return !IsReadOnly();
 }
 
 bool AXNodeObject::CanSetSelectedAttribute() const {
-  // ARIA list box options can be selected if they are children of an element
-  // with an aria-activedescendant attribute.
-  if (AriaRoleAttribute() == kListBoxOptionRole &&
-      AncestorExposesActiveDescendant())
+  const AccessibilityRole role = AriaRoleAttribute();
+  // These elements can be selected if not disabled (native or ARIA)
+  if ((role == kListBoxOptionRole || role == kTreeItemRole ||
+       role == kCellRole || role == kTabRole) &&
+      IsEnabled()) {

[dmazzoni, 2017/05/19 19:54:04]

Do we need to check if the container is enabled or does
IsEnabled do that?

     return true;
+  }
   return AXObjectImpl::CanSetSelectedAttribute();
 }
 
 bool AXNodeObject::CanvasHasFallbackContent() const {
   Node* node = this->GetNode();
   if (!isHTMLCanvasElement(node))
     return false;
 
   // If it has any children that are elements, we'll assume it might be fallback
   // content. If it has no children or its only children are not elements
@@ skipping 1903 matching lines @@
     return String();
   return ToTextControlElement(node)->StrippedPlaceholder();
 }
 
 DEFINE_TRACE(AXNodeObject) {
   visitor->Trace(node_);
   AXObjectImpl::Trace(visitor);
 }
 
 }  // namespace blink