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

include/core/SkPicture.h

Index: include/core/SkPicture.h
diff --git a/include/core/SkPicture.h b/include/core/SkPicture.h
index c398d3a4ec5f4753a38f7fedd896b9e4de3a0e10..c2d05f9c41ef86f3f0c199f8f37faf5712418e08 100644
--- a/include/core/SkPicture.h
+++ b/include/core/SkPicture.h
@@ -224,10 +224,11 @@ private:
     // V47: Add occluder rect to SkBlurMaskFilter
     // V48: Read and write extended SkTextBlobs.
     // V49: Gradients serialized as SkColor4f + SkColorSpace
+    // V50: SkXfermode -> SkBlendMode
 
     // Only SKPs within the min/current picture version range (inclusive) can be read.
     static const uint32_t     MIN_PICTURE_VERSION = 35;     // Produced by Chrome M39.
-    static const uint32_t CURRENT_PICTURE_VERSION = 49;
+    static const uint32_t CURRENT_PICTURE_VERSION = 50;
 
     static_assert(MIN_PICTURE_VERSION <= 41,
                   "Remove kFontFileName and related code from SkFontDescriptor.cpp.");