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

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

 /*
  * Copyright (C) 2008, 2009, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Nuanti Ltd.
  *
  * 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.
@@ skipping 686 matching lines @@
     virtual String placeholder(AXNameFrom, AXDescriptionFrom) const { return String(); }
 
     // Internal function used by name and description, above.
     typedef HeapHashSet<Member<const AXObject>> AXObjectSet;
     virtual String textAlternative(bool recursive, bool inAriaLabelledByTraversal, AXObjectSet& visited, AXNameFrom& nameFrom, AXRelatedObjectVector* relatedObjects, NameSources* nameSources) const { return String(); }
 
     // Returns result of Accessible Name Calculation algorithm.
     // This is a simpler high-level interface to |name| used by Inspector.
     String computedName() const;
 
+    // Internal function used to determine whether the result of calling |name| on this object would
+    // return text that came from the an HTML label element or not. This is intended to be faster than calling
+    // |name| or |textAlternative|, and without side effects (it won't call axObjectCache->getOrCreate).
+    virtual bool nameFromLabelElement() const { return false; }
+
     //
     // Properties of static elements.
     //
 
     virtual const AtomicString& accessKey() const { return nullAtom; }
     virtual RGBA32 backgroundColor() const { return Color::transparent; }
     virtual RGBA32 color() const { return Color::black; }
     // Used by objects of role ColorWellRole.
     virtual RGBA32 colorValue() const { return Color::transparent; }
     virtual bool canvasHasFallbackContent() const { return false; }
@@ skipping 257 matching lines @@
 #define DEFINE_AX_OBJECT_TYPE_CASTS(thisType, predicate) \
     DEFINE_TYPE_CASTS(thisType, AXObject, object, object->predicate, object.predicate)
 
 } // namespace blink
 
 WTF_ALLOW_INIT_WITH_MEM_FUNCTIONS(blink::IgnoredReason);
 WTF_ALLOW_INIT_WITH_MEM_FUNCTIONS(blink::NameSource);
 WTF_ALLOW_INIT_WITH_MEM_FUNCTIONS(blink::DescriptionSource);
 
 #endif // AXObject_h