Made ARIA alerts have an implicit aria-atomic of true and strengthened tests concerning aria-atomic…

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 1100 matching lines @@
 
 const AtomicString& AXObject::containerLiveRegionRelevant() const
 {
     updateCachedAttributeValuesIfNeeded();
     return m_cachedLiveRegionRoot ? m_cachedLiveRegionRoot->liveRegionRelevant() : nullAtom;
 }
 
 bool AXObject::containerLiveRegionAtomic() const
 {
     updateCachedAttributeValuesIfNeeded();
-    return m_cachedLiveRegionRoot ? m_cachedLiveRegionRoot->liveRegionAtomic() : false;
+    return m_cachedLiveRegionRoot && m_cachedLiveRegionRoot->liveRegionAtomic();
 }
 
 bool AXObject::containerLiveRegionBusy() const
 {
     updateCachedAttributeValuesIfNeeded();
-    return m_cachedLiveRegionRoot ? m_cachedLiveRegionRoot->liveRegionBusy() : false;
+    return m_cachedLiveRegionRoot && m_cachedLiveRegionRoot->liveRegionBusy();
 }
 
 void AXObject::markCachedElementRectDirty() const
 {
     for (const auto& child : m_children)
         child->markCachedElementRectDirty();
 }
 
 IntPoint AXObject::clickPoint()
 {
@@ skipping 610 matching lines @@
 
 DEFINE_TRACE(AXObject)
 {
     visitor->trace(m_children);
     visitor->trace(m_parent);
     visitor->trace(m_cachedLiveRegionRoot);
     visitor->trace(m_axObjectCache);
 }
 
 } // namespace blink