Remove prefixed Shadow DOM APIs in Element.

Source/core/frame/UseCounter.h

 /*
  * 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 116 matching lines @@
         DocumentClear = 74,
         SVGFontElement = 76,
         XMLDocument = 77,
         XSLProcessingInstruction = 78,
         XSLTProcessor = 79,
         SVGSwitchElement = 80,
         DocumentAll = 83,
         FormElement = 84,
         DemotedFormElement = 85,
         CaptureAttributeAsEnum = 86,
-        ShadowDOMPrefixedCreateShadowRoot = 88,
-        ShadowDOMPrefixedShadowRoot = 89,
         SVGAnimationElement = 90,
         KeyboardEventKeyLocation = 91,
         LineClamp = 96,
         SubFrameBeforeUnloadRegistered = 97,
         SubFrameBeforeUnloadFired = 98,
         CSSPseudoElementPrefixedDistributed = 99,
         TextReplaceWholeText = 100,
         PrefixedShadowRootConstructor = 101,
         ConsoleMarkTimeline = 102,
         CSSPseudoElementUserAgentCustomPseudo = 103,
@@ skipping 224 matching lines @@
 
     void updateMeasurements();
 
     OwnPtr<BitVector> m_countBits;
     BitVector m_CSSFeatureBits;
 };
 
 } // namespace WebCore
 
 #endif // UseCounter_h