ARIA role status should have a implicit aria-atomic value of true.

Source/modules/accessibility/AXRenderObject.cpp

 /*
 * Copyright (C) 2008 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 1129 matching lines @@
 
     // Default aria-relevant = "additions text".
     if (relevant.isEmpty())
         return defaultLiveRegionRelevant;
 
     return relevant;
 }
 
 bool AXRenderObject::liveRegionAtomic() const
 {
+    // ARIA role status should have implicit aria-atomic value of true.
+    if (getAttribute(aria_atomicAttr).isEmpty() && roleValue() == StatusRole)
+        return true;
     return elementAttributeValue(aria_atomicAttr);
 }
 
 bool AXRenderObject::liveRegionBusy() const
 {
     return elementAttributeValue(aria_busyAttr);
 }
 
 //
 // Accessibility Text.
@@ skipping 1248 matching lines @@
         if (label && label->renderer()) {
             LayoutRect labelRect = axObjectCache()->getOrCreate(label)->elementRect();
             result.unite(labelRect);
         }
     }
 
     return result;
 }
 
 } // namespace blink