Remove calculateStdDeviation function from Blur effect.

Source/platform/graphics/filters/FEDropShadow.h

 /*
  * Copyright (C) Research In Motion Limited 2011. All rights reserved.
  * Copyright (C) 2013 Google Inc. 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
  * version 2 of the License, or (at your option) any later version.
  *
  * This library is distributed in the hope that it will be useful,
@@ skipping 31 matching lines @@
 
     float dy() const { return m_dy; }
     void setDy(float dy) { m_dy = dy; }
 
     Color shadowColor() const { return m_shadowColor; }
     void setShadowColor(const Color& shadowColor) { m_shadowColor = shadowColor; }
 
     float shadowOpacity() const { return m_shadowOpacity; }
     void setShadowOpacity(float shadowOpacity) { m_shadowOpacity = shadowOpacity; }
 
-    static float calculateStdDeviation(float);
-
     virtual FloatRect mapRect(const FloatRect&, bool forward = true) OVERRIDE FINAL;
 
     virtual TextStream& externalRepresentation(TextStream&, int indention) const OVERRIDE;
     virtual PassRefPtr<SkImageFilter> createImageFilter(SkiaImageFilterBuilder*) OVERRIDE;
 
 private:
     FEDropShadow(Filter*, float, float, float, float, const Color&, float);
 
     virtual void applySoftware() OVERRIDE;
 
     float m_stdX;
     float m_stdY;
     float m_dx;
     float m_dy;
     Color m_shadowColor;
     float m_shadowOpacity;
 };
 
 } // namespace WebCore
 
 #endif // FEDropShadow_h