Revert of Add SkRasterPipeline blitter.

src/core/SkXfermode.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkXfermode.h"
 #include "SkXfermode_proccoeff.h"
 #include "SkColorPriv.h"
@@ skipping 1402 matching lines @@
 
 bool SkXfermode::IsOpaque(const SkXfermode* xfer, SrcColorOpacity opacityType) {
     // if xfer is nullptr we treat it as srcOver which is opaque if our src is opaque
     if (!xfer) {
         return SkXfermode::kOpaque_SrcColorOpacity == opacityType;
     }
 
     return xfer->isOpaque(opacityType);
 }
 
-bool SkXfermode::appendStages(SkRasterPipeline* pipeline) const {
-    return this->onAppendStages(pipeline);
-}
-
-bool SkXfermode::onAppendStages(SkRasterPipeline*) const {
-    return false;
-}
-
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_START(SkXfermode)
     SK_DEFINE_FLATTENABLE_REGISTRAR_ENTRY(SkProcCoeffXfermode)
 SK_DEFINE_FLATTENABLE_REGISTRAR_GROUP_END