switch xfermodes over to sk_sp

tests/XfermodeTest.cpp

Index: tests/XfermodeTest.cpp
diff --git a/tests/XfermodeTest.cpp b/tests/XfermodeTest.cpp
index 294d63db59adb490f4045d2752f1660c467bd8ce..c3a4d967852308fe147880fd5754fe3ed768c85c 100644
--- a/tests/XfermodeTest.cpp
+++ b/tests/XfermodeTest.cpp
@@ -13,7 +13,7 @@
 
 static void test_asMode(skiatest::Reporter* reporter) {
     for (int mode = 0; mode <= SkXfermode::kLastMode; mode++) {
-        SkXfermode* xfer = SkXfermode::Create((SkXfermode::Mode) mode);
+        auto xfer = SkXfermode::Make((SkXfermode::Mode) mode);
 
         SkXfermode::Mode reportedMode = ILLEGAL_MODE;
         REPORTER_ASSERT(reporter, reportedMode != mode);
@@ -27,7 +27,6 @@ static void test_asMode(skiatest::Reporter* reporter) {
             reportedMode = (SkXfermode::Mode) -1;
             REPORTER_ASSERT(reporter, xfer->asMode(&reportedMode));
             REPORTER_ASSERT(reporter, reportedMode == mode);
-            xfer->unref();
         } else {
             REPORTER_ASSERT(reporter, SkXfermode::kSrcOver_Mode == mode);
         }
@@ -41,9 +40,8 @@ static void test_IsMode(skiatest::Reporter* reporter) {
     for (int i = 0; i <= SkXfermode::kLastMode; ++i) {
         SkXfermode::Mode mode = (SkXfermode::Mode)i;
 
-        SkXfermode* xfer = SkXfermode::Create(mode);
+        auto xfer = SkXfermode::Make(mode);
         REPORTER_ASSERT(reporter, SkXfermode::IsMode(xfer, mode));
-        SkSafeUnref(xfer);
 
         if (SkXfermode::kSrcOver_Mode != mode) {
             REPORTER_ASSERT(reporter, !SkXfermode::IsMode(nullptr, mode));