Refactor shadow rendering logic.

Source/core/html/canvas/CanvasRenderingContext2D.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2007 Alp Toker <alp@atoker.com>
  * Copyright (C) 2008 Eric Seidel <eric@webkit.org>
  * Copyright (C) 2008 Dirk Schulze <krit@webkit.org>
  * Copyright (C) 2010 Torch Mobile (Beijing) Co. Ltd. All rights reserved.
  * Copyright (C) 2012 Intel Corporation. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated. All rights reserved.
  *
@@ skipping 1166 matching lines @@
     applyShadow();
 }
 
 void CanvasRenderingContext2D::applyShadow()
 {
     GraphicsContext* c = drawingContext();
     if (!c)
         return;
 
     if (shouldDrawShadows())
-        c->setShadow(state().m_shadowOffset, state().m_shadowBlur, state().m_shadowColor, ColorSpaceDeviceRGB);
+        c->setShadow(state().m_shadowOffset, state().m_shadowBlur, state().m_shadowColor);
     else
         c->clearShadow();
 }
 
 bool CanvasRenderingContext2D::shouldDrawShadows() const
 {
     return alphaChannel(state().m_shadowColor) && (state().m_shadowBlur || !state().m_shadowOffset.isZero());
 }
 
 static LayoutSize size(HTMLImageElement* image)
@@ skipping 1052 matching lines @@
 }
 
 PassRefPtr<Canvas2DContextAttributes> CanvasRenderingContext2D::getContextAttributes() const
 {
     RefPtr<Canvas2DContextAttributes> attributes = Canvas2DContextAttributes::create();
     attributes->setAlpha(m_hasAlpha);
     return attributes.release();
 }
 
 } // namespace WebCore