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

gm/bitmaprect.cpp

Index: gm/bitmaprect.cpp
diff --git a/gm/bitmaprect.cpp b/gm/bitmaprect.cpp
index 2a813004dff5205a74ec1e0444e6428724046b55..06bf36a91d4f38c19915bf4ae3701ce0889f6452 100644
--- a/gm/bitmaprect.cpp
+++ b/gm/bitmaprect.cpp
@@ -201,7 +201,7 @@ protected:
     void onDraw(SkCanvas* canvas) override {
         SkPaint paint;
         paint.setAlpha(128);
-        paint.setXfermode(SkXfermode::Make(SkXfermode::kXor_Mode));
+        paint.setBlendMode(SkBlendMode::kXor);
 
         SkRect srcR1 = { 0.0f, 0.0f, 4096.0f, 2040.0f };
         SkRect dstR1 = { 10.1f, 10.1f, 629.9f, 400.9f };