Removing the dependency on GraphicsContext for drawing images in 2D canvas

Source/core/layout/LayoutThemeMac.mm

 /*
  * Copyright (C) 2005, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
  * Copyright (C) 2008, 2009 Google, Inc.
  *
  * 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 1332 matching lines @@
     }
 
     FloatRect borderBounds = unzoomedRect;
     borderBounds.inflate(sliderThumbBorderWidth / 2.0);
 
     borderBounds.inflate(-sliderThumbBorderWidth);
     FloatSize shadowOffset(0, 1);
     paintInfo.context->setShadow(shadowOffset, sliderThumbShadowBlur, shadowColor);
     paintInfo.context->setFillColor(Color::black);
     paintInfo.context->fillEllipse(borderBounds);
-    paintInfo.context->clearShadow();
+    paintInfo.context->clearDrawLooper();
 
     IntRect fillBounds = enclosedIntRect(unzoomedRect);
     RefPtr<Gradient> fillGradient = Gradient::create(fillBounds.minXMinYCorner(), fillBounds.minXMaxYCorner());
     fillGradient->addColorStop(0.0, fillGradientTopColor);
     fillGradient->addColorStop(0.52, fillGradientUpperMiddleColor);
     fillGradient->addColorStop(0.52, fillGradientLowerMiddleColor);
     fillGradient->addColorStop(1.0, fillGradientBottomColor);
     paintInfo.context->setFillGradient(fillGradient);
     paintInfo.context->fillEllipse(borderBounds);
 
@@ skipping 480 matching lines @@
 
 bool LayoutThemeMac::shouldUseFallbackTheme(const ComputedStyle& style) const
 {
     ControlPart part = style.appearance();
     if (part == CheckboxPart || part == RadioPart)
         return style.effectiveZoom() != 1;
     return false;
 }
 
 } // namespace blink