Use refs for GraphicsContext

third_party/WebKit/Source/platform/graphics/skia/SkiaUtils.h

 /*
  * Copyright (c) 2006,2007,2008, 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 85 matching lines @@
     return RULE_NONZERO;
 }
 
 // Determine if a given WebKit point is contained in a path
 bool SkPathContainsPoint(const SkPath&, const FloatPoint&, SkPath::FillType);
 
 SkMatrix PLATFORM_EXPORT affineTransformToSkMatrix(const AffineTransform&);
 
 bool nearlyIntegral(float value);
 
-InterpolationQuality limitInterpolationQuality(const GraphicsContext*, InterpolationQuality resampling);
+InterpolationQuality limitInterpolationQuality(const GraphicsContext&, InterpolationQuality resampling);
 
 InterpolationQuality computeInterpolationQuality(
     float srcWidth,
     float srcHeight,
     float destWidth,
     float destHeight,
     bool isDataComplete = true);
 
 // This replicates the old skia behavior when it used to take radius for blur. Now it takes sigma.
 inline SkScalar skBlurRadiusToSigma(SkScalar radius)
 {
     SkASSERT(radius >= 0);
     return 0.288675f * radius;
 }
 
 template<typename PrimitiveType>
 void drawPlatformFocusRing(const PrimitiveType&, SkCanvas*, SkColor, int width);
 
 // TODO(fmalita): remove in favor of direct SrcRectConstraint use.
 inline SkCanvas::SrcRectConstraint WebCoreClampingModeToSkiaRectConstraint(Image::ImageClampingMode clampMode)
 {
     return clampMode == Image::ClampImageToSourceRect
         ? SkCanvas::kStrict_SrcRectConstraint
         : SkCanvas::kFast_SrcRectConstraint;
 }
 
 } // namespace blink
 
 #endif  // SkiaUtils_h