Add constant twoPiDouble/twoPiFloat to MathExtras.h

Source/core/svg/SVGPathParser.cpp

 /*
  * Copyright (C) 2002, 2003 The Karbon Developers
  * Copyright (C) 2006 Alexander Kellett <lypanov@kde.org>
  * Copyright (C) 2006, 2007 Rob Buis <buis@kde.org>
  * Copyright (C) 2007, 2009 Apple Inc. All rights reserved.
  * Copyright (C) Research In Motion Limited 2010. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
@@ skipping 438 matching lines @@
     delta.scale(scaleFactor);
     FloatPoint centerPoint = point1 + point2;
     centerPoint.scale(0.5f, 0.5f);
     centerPoint.move(-delta.height(), delta.width());
 
     float theta1 = FloatPoint(point1 - centerPoint).slopeAngleRadians();
     float theta2 = FloatPoint(point2 - centerPoint).slopeAngleRadians();
 
     float thetaArc = theta2 - theta1;
     if (thetaArc < 0 && sweepFlag)
-        thetaArc += 2 * piFloat;
+        thetaArc += twoPiFloat;
     else if (thetaArc > 0 && !sweepFlag)
-        thetaArc -= 2 * piFloat;
+        thetaArc -= twoPiFloat;
 
     pointTransform.makeIdentity();
     pointTransform.rotate(angle);
     pointTransform.scale(rx, ry);
 
     // Some results of atan2 on some platform implementations are not exact enough. So that we get more
     // cubic curves than expected here. Adding 0.001f reduces the count of sgements to the correct count.
     int segments = ceilf(fabsf(thetaArc / (piOverTwoFloat + 0.001f)));
     for (int i = 0; i < segments; ++i) {
         float startTheta = theta1 + i * thetaArc / segments;
@@ skipping 14 matching lines @@
         point2 = targetPoint;
         point2.move(t * sinEndTheta, -t * cosEndTheta);
 
         m_consumer->curveToCubic(pointTransform.mapPoint(point1), pointTransform.mapPoint(point2),
                                  pointTransform.mapPoint(targetPoint), AbsoluteCoordinates);
     }
     return true;
 }
 
 }