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

gm/drawatlascolor.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "gm.h"
 #include "SkCanvas.h"
 #include "SkRSXform.h"
 #include "SkSurface.h"
 
 // Create a square atlas of:
 //   opaque white  |     opaque red
 //  ------------------------------------
 //   opaque green  |  transparent black
 //
 static sk_sp<SkImage> make_atlas(SkCanvas* caller, int atlasSize) {
     const int kBlockSize = atlasSize/2;
 
     SkImageInfo info = SkImageInfo::MakeN32Premul(atlasSize, atlasSize);
     auto surface(caller->makeSurface(info));
     if (nullptr == surface) {
         surface = SkSurface::MakeRaster(info);
     }
     SkCanvas* canvas = surface->getCanvas();
 
     SkPaint paint;
-    paint.setXfermode(SkXfermode::Make(SkXfermode::kSrc_Mode));
+    paint.setBlendMode(SkBlendMode::kSrc);
 
     paint.setColor(SK_ColorWHITE);
     SkRect r = SkRect::MakeXYWH(0, 0,
                                 SkIntToScalar(kBlockSize), SkIntToScalar(kBlockSize));
     canvas->drawRect(r, paint);
 
     paint.setColor(SK_ColorRED);
     r = SkRect::MakeXYWH(SkIntToScalar(kBlockSize), 0,
                          SkIntToScalar(kBlockSize), SkIntToScalar(kBlockSize));
     canvas->drawRect(r, paint);
@@ skipping 122 matching lines @@
 private:
     static constexpr int kNumXferModes = 29;
     static constexpr int kNumColors = 4;
     static constexpr int kAtlasSize = 30;
     static constexpr int kPad = 2;
     static constexpr int kTextPad = 8;
 
     typedef GM INHERITED;
 };
 DEF_GM( return new DrawAtlasColorsGM; )