switch xfermodes over to sk_sp

tests/PaintTest.cpp

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBlurMask.h"
 #include "SkBlurMaskFilter.h"
 #include "SkLayerDrawLooper.h"
@@ skipping 274 matching lines @@
     REPORTER_ASSERT(reporter, r.isEmpty());
 }
 
 #define ASSERT(expr) REPORTER_ASSERT(r, expr)
 
 DEF_TEST(Paint_MoreFlattening, r) {
     SkPaint paint;
     paint.setColor(0x00AABBCC);
     paint.setTextScaleX(1.0f);  // Default value, ignored.
     paint.setTextSize(19);
-    paint.setXfermode(SkXfermode::Create(SkXfermode::kModulate_Mode))->unref();
+    paint.setXfermode(SkXfermode::Make(SkXfermode::kModulate_Mode));
     paint.setLooper(nullptr);  // Default value, ignored.
 
     SkWriteBuffer writer;
     paint.flatten(writer);
 
     SkReadBuffer reader(writer.getWriter32()->contiguousArray(), writer.bytesWritten());
     SkPaint other;
     other.unflatten(reader);
     ASSERT(reader.offset() == writer.bytesWritten());
 
@@ skipping 54 matching lines @@
 
     SkColorMatrix cm;
     cm.setIdentity();   // does not change alpha
     paint.setColorFilter(SkColorFilter::MakeMatrixFilterRowMajor255(cm.fMat));
     REPORTER_ASSERT(r, paint.nothingToDraw());
 
     cm.postTranslate(0, 0, 0, 1);    // wacks alpha
     paint.setColorFilter(SkColorFilter::MakeMatrixFilterRowMajor255(cm.fMat));
     REPORTER_ASSERT(r, !paint.nothingToDraw());
 }