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

src/core/SkBlitter_ARGB32.cpp

Index: src/core/SkBlitter_ARGB32.cpp
diff --git a/src/core/SkBlitter_ARGB32.cpp b/src/core/SkBlitter_ARGB32.cpp
index aada0586a4b2dfb0bd7e2e9ae221b613b41138d1..ea0554d66eaaa8aac3f1c9788732da837641e74a 100644
--- a/src/core/SkBlitter_ARGB32.cpp
+++ b/src/core/SkBlitter_ARGB32.cpp
@@ -339,8 +339,7 @@ SkARGB32_Shader_Blitter::SkARGB32_Shader_Blitter(const SkPixmap& device,
 {
     fBuffer = (SkPMColor*)sk_malloc_throw(device.width() * (sizeof(SkPMColor)));
 
-    fXfermode = paint.getXfermode();
-    SkSafeRef(fXfermode);
+    fXfermode = SkXfermode::Peek(paint.getBlendMode());
 
     int flags = 0;
     if (!(shaderContext->getFlags() & SkShader::kOpaqueAlpha_Flag)) {
@@ -370,7 +369,6 @@ SkARGB32_Shader_Blitter::SkARGB32_Shader_Blitter(const SkPixmap& device,
 }
 
 SkARGB32_Shader_Blitter::~SkARGB32_Shader_Blitter() {
-    SkSafeUnref(fXfermode);
     sk_free(fBuffer);
 }