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

tools/sk_tool_utils.cpp

 /*
  * Copyright 2014 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 "sk_tool_utils_flags.h"
 
@@ skipping 202 matching lines @@
     bitmap.allocPixels(SkImageInfo::MakeS32(w, h, kPremul_SkAlphaType));
     SkCanvas canvas(bitmap);
 
     sk_tool_utils::draw_checkerboard(&canvas, c1, c2, checkSize);
     return bitmap;
 }
 
 void draw_checkerboard(SkCanvas* canvas, SkColor c1, SkColor c2, int size) {
     SkPaint paint;
     paint.setShader(create_checkerboard_shader(c1, c2, size));
-    paint.setXfermodeMode(SkXfermode::kSrc_Mode);
+    paint.setBlendMode(SkBlendMode::kSrc);
     canvas->drawPaint(paint);
 }
 
 SkBitmap create_string_bitmap(int w, int h, SkColor c, int x, int y,
                               int textSize, const char* str) {
     SkBitmap bitmap;
     bitmap.allocN32Pixels(w, h);
     SkCanvas canvas(bitmap);
 
     SkPaint paint;
@@ skipping 305 matching lines @@
     const SkVector& ll = rr.radii(SkRRect::kLowerLeft_Corner);
 
     SkScalar maxL = SkTMax(ul.fX, ll.fX);
     SkScalar maxR = SkTMax(ur.fX, lr.fX);
 
     return SkRect::MakeLTRB(r.fLeft + maxL, r.fTop, r.fRight - maxR, r.fBottom);
 }
 
 
 }  // namespace sk_tool_utils