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

samplecode/SampleQuadStroker.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "sk_tool_utils.h"
 #include "SampleCode.h"
 #include "SkView.h"
@@ skipping 230 matching lines @@
 
      void copyMinToMax() {
         erase(fMaxSurface);
         SkCanvas* canvas = fMaxSurface->getCanvas();
         canvas->save();
         canvas->concat(fMatrix);
         fMinSurface->draw(canvas, 0, 0, nullptr);
         canvas->restore();
 
         SkPaint paint;
-        paint.setXfermodeMode(SkXfermode::kClear_Mode);
+        paint.setBlendMode(SkBlendMode::kClear);
         for (int iy = 1; iy < fH; ++iy) {
             SkScalar y = SkIntToScalar(iy * fZoom);
             canvas->drawLine(0, y - SK_ScalarHalf, 999, y - SK_ScalarHalf, paint);
         }
         for (int ix = 1; ix < fW; ++ix) {
             SkScalar x = SkIntToScalar(ix * fZoom);
             canvas->drawLine(x - SK_ScalarHalf, 0, x - SK_ScalarHalf, 999, paint);
         }
     }
 
@@ skipping 530 matching lines @@
     }
 
 private:
     typedef SkView INHERITED;
 };
 
 ///////////////////////////////////////////////////////////////////////////////
 
 static SkView* F2() { return new QuadStrokerView; }
 static SkViewRegister gR2(F2);