Make beginLayer() and CanvasRenderingContext2D use SkXfermode::Mode.

Source/core/rendering/svg/RenderSVGResourceClipper.cpp

 /*
  * Copyright (C) 2004, 2005, 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Rob Buis <buis@kde.org>
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  * Copyright (C) 2011 Dirk Schulze <krit@webkit.org>
  *
  * 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.
@@ skipping 182 matching lines @@
             return false;
         }
 
         drawClipMaskContent(context, targetBoundingBox);
 
         if (clipPathClipper)
             clipPathClipper->postApplyStatefulResource(this, context, clipPathClipperState);
     }
 
     // Masked content layer start.
-    context->beginLayer(1, CompositeSourceIn, &paintInvalidationRect);
+    context->beginLayer(1, SkXfermode::kSrcIn_Mode, &paintInvalidationRect);
 
     return true;
 }
 
 void RenderSVGResourceClipper::postApplyStatefulResource(RenderObject* target, GraphicsContext*& context, ClipperState& clipperState)
 {
     switch (clipperState) {
     case ClipperAppliedPath:
         // Path-only clipping, no layers to restore but we need to emit an end to the clip path display item.
         {
@@ skipping 151 matching lines @@
         AffineTransform transform;
         transform.translate(objectBoundingBox.x(), objectBoundingBox.y());
         transform.scaleNonUniform(objectBoundingBox.width(), objectBoundingBox.height());
         return transform.mapRect(m_clipBoundaries);
     }
 
     return m_clipBoundaries;
 }
 
 }