Remove meaningless uses of [TypeChecking=Nullable]

Source/core/svg/SVGMarkerElement.idl

 /*
  * Copyright (C) 2006 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
  *    notice, this list of conditions and the following disclaimer in the
  *    documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``AS IS'' AND ANY
  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
  * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
  * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
  * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 // http://www.w3.org/TR/SVG2/painting.html#InterfaceSVGMarkerElement
 
 [
-    TypeChecking=Interface|Nullable,
+    TypeChecking=Interface,
 ] interface SVGMarkerElement : SVGElement {
 
     // Marker Unit Types
     const unsigned short SVG_MARKERUNITS_UNKNOWN = 0;
     const unsigned short SVG_MARKERUNITS_USERSPACEONUSE = 1;
     const unsigned short SVG_MARKERUNITS_STROKEWIDTH = 2;
 
     // Marker Orientation Types
     const unsigned short SVG_MARKER_ORIENT_UNKNOWN = 0;
     const unsigned short SVG_MARKER_ORIENT_AUTO = 1;
     const unsigned short SVG_MARKER_ORIENT_ANGLE = 2;
 
     readonly attribute SVGAnimatedLength refX;
     readonly attribute SVGAnimatedLength refY;
     readonly attribute SVGAnimatedEnumeration markerUnits;
     readonly attribute SVGAnimatedLength markerWidth;
     readonly attribute SVGAnimatedLength markerHeight;
     readonly attribute SVGAnimatedEnumeration orientType;
     readonly attribute SVGAnimatedAngle orientAngle;
 
     void setOrientToAuto();
     void setOrientToAngle(SVGAngle angle);
 };
 
 SVGMarkerElement implements SVGFitToViewBox;