Implement SetWrapperReferenceTo idl attribute within traceWrappers for svg elements

third_party/WebKit/Source/core/svg/SVGAngleTearOff.h

 /*
  * Copyright (C) 2014 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 51 matching lines @@
 
     void setValueInSpecifiedUnits(float, ExceptionState&);
     float valueInSpecifiedUnits() { return target()->valueInSpecifiedUnits(); }
 
     void newValueSpecifiedUnits(unsigned short unitType, float valueInSpecifiedUnits, ExceptionState&);
     void convertToSpecifiedUnits(unsigned short unitType, ExceptionState&);
 
     String valueAsString() { return hasExposedAngleUnit() ? target()->valueAsString() : String::number(0); }
     void setValueAsString(const String&, ExceptionState&);
 
+    DECLARE_VIRTUAL_TRACE_WRAPPERS();
+
 private:
     SVGAngleTearOff(SVGAngle*, SVGElement*, PropertyIsAnimValType, const QualifiedName&);
 
     bool hasExposedAngleUnit() { return target()->unitType() <= SVGAngle::SVG_ANGLETYPE_GRAD; }
 };
 
 } // namespace blink
 
 #endif // SVGAngleTearOff_h