Avoid updateStyleAndLayoutTree in determineAccessibilityRole

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 509 matching lines @@
   if ((m_ariaRole = determineAriaRoleAttribute()) != UnknownRole)
     return m_ariaRole;
   if (getNode()->isTextNode())
     return StaticTextRole;
 
   AccessibilityRole role = nativeAccessibilityRoleIgnoringAria();
   if (role != UnknownRole)
     return role;
   if (getNode()->isElementNode()) {
     Element* element = toElement(getNode());
-    if (element->isInCanvasSubtree()) {
-      getDocument()->updateStyleAndLayoutTreeForNode(element);
-      if (element->isFocusable())
-        return GroupRole;
-    }
+    // A generic element with tabIndex explicitly set gets GroupRole.
+    // The layout checks for focusability aren't critical here; a false
+    // positive would be harmless.
+    if (element->isInCanvasSubtree() && element->supportsFocus())
+      return GroupRole;
   }
   return UnknownRole;
 }
 
 AccessibilityRole AXNodeObject::determineAriaRoleAttribute() const {
   const AtomicString& ariaRole = getAttribute(roleAttr);
   if (ariaRole.isNull() || ariaRole.isEmpty())
     return UnknownRole;
 
   AccessibilityRole role = ariaRoleToWebCoreRole(ariaRole);
@@ skipping 2350 matching lines @@
   }
   return placeholder;
 }
 
 DEFINE_TRACE(AXNodeObject) {
   visitor->trace(m_node);
   AXObject::trace(visitor);
 }
 
 }  // namespace blink