Rename {Author,UserAgent}ShadowRoot to {Open,Closed}ShadowRoot.

Source/modules/accessibility/AXSlider.cpp

 /*
  * Copyright (C) 2009 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 130 matching lines @@
 }
 
 LayoutRect AXSliderThumb::elementRect() const
 {
     if (!m_parent)
         return LayoutRect();
 
     LayoutObject* sliderRenderer = m_parent->renderer();
     if (!sliderRenderer || !sliderRenderer->isSlider())
         return LayoutRect();
-    return toElement(sliderRenderer->node())->userAgentShadowRoot()->getElementById(ShadowElementNames::sliderThumb())->boundingBox();
+    return toElement(sliderRenderer->node())->closedShadowRoot()->getElementById(ShadowElementNames::sliderThumb())->boundingBox();
 }
 
 bool AXSliderThumb::computeAccessibilityIsIgnored() const
 {
     return accessibilityIsIgnoredByDefault();
 }
 
 } // namespace blink