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

Source/core/rendering/svg/RenderSVGResourceClipper.cpp

Index: Source/core/rendering/svg/RenderSVGResourceClipper.cpp
diff --git a/Source/core/rendering/svg/RenderSVGResourceClipper.cpp b/Source/core/rendering/svg/RenderSVGResourceClipper.cpp
index 483123471066d724686c58d273ef158cffbfe6a0..91082c2cf3eb4f501ae0dee04737b9e7d8beb4c3 100644
--- a/Source/core/rendering/svg/RenderSVGResourceClipper.cpp
+++ b/Source/core/rendering/svg/RenderSVGResourceClipper.cpp
@@ -200,7 +200,7 @@ bool RenderSVGResourceClipper::applyClippingToContext(RenderObject* target, cons
     }
 
     // Masked content layer start.
-    context->beginLayer(1, CompositeSourceIn, &paintInvalidationRect);
+    context->beginLayer(1, SkXfermode::kSrcIn_Mode, &paintInvalidationRect);
 
     return true;
 }