Remove unpremul/remul from SkArithmeticMode, both raster and GPU, since the SVG spec actually defin…

gm/xfermodeimagefilter.cpp

Index: gm/xfermodeimagefilter.cpp
diff --git a/gm/xfermodeimagefilter.cpp b/gm/xfermodeimagefilter.cpp
index a6d395e658a3044c8d8cf3e2ed5037a165705892..bfea3d42e368a24c75eb9f52ded79fdec3bff4fc 100644
--- a/gm/xfermodeimagefilter.cpp
+++ b/gm/xfermodeimagefilter.cpp
@@ -135,7 +135,7 @@ protected:
             }
         }
         // Test arithmetic mode as image filter
-        SkAutoTUnref<SkXfermode> mode(SkArithmeticMode::Create(0, SK_Scalar1, SK_Scalar1, 0));
+        SkAutoTUnref<SkXfermode> mode(SkArithmeticMode::Create(0, SK_Scalar1, SK_Scalar1, 0, true));
         SkAutoTUnref<SkImageFilter> filter(SkNEW_ARGS(SkXfermodeImageFilter, (mode, background)));
         paint.setImageFilter(filter);
         drawClippedBitmap(canvas, fBitmap, paint, SkIntToScalar(x), SkIntToScalar(y));