Implement nameFromLabelElement to see if a control is associated with a label.

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

 /*
  * Copyright (C) 2008, 2009, 2011 Apple 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 705 matching lines @@
     return axObj.textAlternative(true, inAriaLabelledByTraversal, visited, tmpNameFrom, nullptr, nullptr);
 }
 
 String AXObject::ariaTextAlternative(bool recursive, bool inAriaLabelledByTraversal, AXObjectSet& visited, AXNameFrom& nameFrom, AXRelatedObjectVector* relatedObjects, NameSources* nameSources, bool* foundTextAlternative) const
 {
     String textAlternative;
     bool alreadyVisited = visited.contains(this);
     visited.add(this);
 
     // Step 2A from: http://www.w3.org/TR/accname-aam-1.1
+    // If you change this logic, update AXNodeObject::nameFromLabelElement, too.
     if (!recursive && layoutObject()
         && layoutObject()->style()->visibility() != VISIBLE
         && !equalIgnoringCase(getAttribute(aria_hiddenAttr), "false")) {
         return String();
     }
 
     // Step 2B from: http://www.w3.org/TR/accname-aam-1.1
+    // If you change this logic, update AXNodeObject::nameFromLabelElement, too.
     if (!inAriaLabelledByTraversal && !alreadyVisited) {
         const QualifiedName& attr = hasAttribute(aria_labeledbyAttr) && !hasAttribute(aria_labelledbyAttr) ? aria_labeledbyAttr : aria_labelledbyAttr;
         nameFrom = AXNameFromRelatedElement;
         if (nameSources) {
             nameSources->append(NameSource(*foundTextAlternative, attr));
             nameSources->last().type = nameFrom;
         }
 
         const AtomicString& ariaLabelledby = getAttribute(attr);
         if (!ariaLabelledby.isNull()) {
@@ skipping 13 matching lines @@
                     *foundTextAlternative = true;
                     return textAlternative;
                 }
             } else if (nameSources) {
                 nameSources->last().invalid = true;
             }
         }
     }
 
     // Step 2C from: http://www.w3.org/TR/accname-aam-1.1
+    // If you change this logic, update AXNodeObject::nameFromLabelElement, too.
     nameFrom = AXNameFromAttribute;
     if (nameSources) {
         nameSources->append(NameSource(*foundTextAlternative, aria_labelAttr));
         nameSources->last().type = nameFrom;
     }
     const AtomicString& ariaLabel = getAttribute(aria_labelAttr);
     if (!ariaLabel.isEmpty()) {
         textAlternative = ariaLabel;
 
         if (nameSources) {
@@ skipping 902 matching lines @@
 
 DEFINE_TRACE(AXObject)
 {
     visitor->trace(m_children);
     visitor->trace(m_parent);
     visitor->trace(m_cachedLiveRegionRoot);
     visitor->trace(m_axObjectCache);
 }
 
 } // namespace blink