Revert[8] "replace SkXfermode obj with SkBlendMode enum in paints"

tests/SerializationTest.cpp

Index: tests/SerializationTest.cpp
diff --git a/tests/SerializationTest.cpp b/tests/SerializationTest.cpp
index 9e407015b97e1b13a9053984498165642a7a19c9..26a2da46d87b05608e554a58e64287013afe4fd3 100644
--- a/tests/SerializationTest.cpp
+++ b/tests/SerializationTest.cpp
@@ -260,7 +260,7 @@ static void TestBitmapSerialization(const SkBitmap& validBitmap,
     sk_sp<SkImage> invalidImage(SkImage::MakeFromBitmap(invalidBitmap));
     sk_sp<SkImageFilter> invalidBitmapSource(SkImageSource::Make(std::move(invalidImage)));
     sk_sp<SkImageFilter> xfermodeImageFilter(
-        SkXfermodeImageFilter::Make(SkXfermode::Make(SkXfermode::kSrcOver_Mode),
+        SkXfermodeImageFilter::Make(SkBlendMode::kSrcOver,
                                     std::move(invalidBitmapSource),
                                     std::move(validBitmapSource), nullptr));