Refactoring DrawLooper so that it can apply shadow effects as skia image filters

Source/core/platform/graphics/GraphicsContext.h

 /*
  * Copyright (C) 2003, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008-2009 Torch Mobile, Inc.
  * Copyright (C) 2013 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
@@ skipping 110 matching lines @@
     Color fillColor() const { return m_state->m_fillColor; }
     void setFillColor(const Color&);
     SkColor effectiveFillColor() const { return m_state->applyAlpha(m_state->m_fillColor.rgb()); }
 
     void setFillPattern(PassRefPtr<Pattern>);
     Pattern* fillPattern() const { return m_state->m_fillPattern.get(); }
 
     void setFillGradient(PassRefPtr<Gradient>);
     Gradient* fillGradient() const { return m_state->m_fillGradient.get(); }
 
-    SkDrawLooper* drawLooper() const { return m_state->m_looper.get(); }
+    DrawLooper* drawLooper() const { return m_state->m_looper.get(); }
     SkColor effectiveStrokeColor() const { return m_state->applyAlpha(m_state->m_strokeData.color().rgb()); }
 
     int getNormalizedAlpha() const;
 
     bool getClipBounds(SkRect* bounds) const;
     const SkMatrix& getTotalMatrix() const;
     bool isPrintingDevice() const;
 
     void setShouldAntialias(bool antialias) { m_state->m_shouldAntialias = antialias; }
     bool shouldAntialias() const { return m_state->m_shouldAntialias; }
@@ skipping 154 matching lines @@
     void endTransparencyLayer();
 
     bool hasShadow() const;
     void setShadow(const FloatSize& offset, float blur, const Color&,
         DrawLooper::ShadowTransformMode = DrawLooper::ShadowRespectsTransforms,
         DrawLooper::ShadowAlphaMode = DrawLooper::ShadowRespectsAlpha);
     void clearShadow() { clearDrawLooper(); }
 
     // It is assumed that this draw looper is used only for shadows
     // (i.e. a draw looper is set if and only if there is a shadow).
-    void setDrawLooper(const DrawLooper&);
+    void setDrawLooper(PassRefPtr<DrawLooper>);
     void clearDrawLooper();
 
     void drawFocusRing(const Vector<IntRect>&, int width, int offset, const Color&);
     void drawFocusRing(const Path&, int width, int offset, const Color&);
 
     enum Edge {
         NoEdge = 0,
         TopEdge = 1 << 1,
         RightEdge = 1 << 2,
         BottomEdge = 1 << 3,
@@ skipping 147 matching lines @@
     // FIXME: Make this go away: crbug.com/236892
     bool m_updatingControlTints : 1;
     bool m_accelerated : 1;
     bool m_isCertainlyOpaque : 1;
     bool m_printing : 1;
 };
 
 } // namespace WebCore
 
 #endif // GraphicsContext_h