switch xfermodes over to sk_sp

bench/Xfer4fBench.cpp

Index: bench/Xfer4fBench.cpp
diff --git a/bench/Xfer4fBench.cpp b/bench/Xfer4fBench.cpp
index bc234a7edbeb14b19786b54f663c846420184dda..92016264b113e97dd5bb06aa656cc1aebbeb037c 100644
--- a/bench/Xfer4fBench.cpp
+++ b/bench/Xfer4fBench.cpp
@@ -21,7 +21,7 @@ public:
         : fDoN(doN)
         , fFlags(flags & ~USE_AA)
     {
-        fXfer.reset(SkXfermode::Create(mode));
+        fXfer = SkXfermode::Make(mode);
         
         fProc1 = SkXfermode::GetD32Proc(fXfer, fFlags | SkXfermode::kSrcIsSingle_D32Flag);
         fProcN = SkXfermode::GetD32Proc(fXfer, fFlags);
@@ -53,15 +53,15 @@ protected:
     void onDraw(int loops, SkCanvas*) override {
         for (int i = 0; i < loops * INNER_LOOPS; ++i) {
             if (fDoN) {
-                fProcN(fXfer, fDst, fSrc, N, fAA);
+                fProcN(fXfer.get(), fDst, fSrc, N, fAA);
             } else {
-                fProc1(fXfer, fDst, fSrc, N, fAA);
+                fProc1(fXfer.get(), fDst, fSrc, N, fAA);
             }
         }
     }
 
 private:
-    SkAutoTUnref<SkXfermode> fXfer;
+    sk_sp<SkXfermode>   fXfer;
     SkString             fName;
     SkXfermode::D32Proc  fProc1;
     SkXfermode::D32Proc  fProcN;