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

src/core/SkRasterPipelineBlitter.cpp

Index: src/core/SkRasterPipelineBlitter.cpp
diff --git a/src/core/SkRasterPipelineBlitter.cpp b/src/core/SkRasterPipelineBlitter.cpp
index 1e8dcf59e0cf16c501f5f55d6e62e0bd6e12f8df..91d60bee3aac10f2e65b712cd72be4990cdbce66 100644
--- a/src/core/SkRasterPipelineBlitter.cpp
+++ b/src/core/SkRasterPipelineBlitter.cpp
@@ -82,8 +82,8 @@ SkBlitter* SkRasterPipelineBlitter::Create(const SkPixmap& dst,
     }
 
     SkRasterPipeline shader, colorFilter, xfermode;
-    if (!append_effect_stages(paint.getColorFilter(), &colorFilter) ||
-        !append_effect_stages(paint.getXfermode(),    &xfermode   )) {
+    if (!append_effect_stages(paint.getColorFilter(),                 &colorFilter) ||
+        !append_effect_stages(SkXfermode::Peek(paint.getBlendMode()), &xfermode   )) {
         return nullptr;
     }
 
@@ -104,7 +104,7 @@ SkBlitter* SkRasterPipelineBlitter::Create(const SkPixmap& dst,
     if (!paint.getShader()) {
         blitter->fShader.append(SkRasterPipeline::constant_color, &blitter->fPaintColor);
     }
-    if (!paint.getXfermode()) {
+    if (paint.isSrcOver()) {
         blitter->fXfermode.append(SkRasterPipeline::srcover);
     }