switch xfermodes over to sk_sp

include/client/android/SkAvoidXfermode.h

Index: include/client/android/SkAvoidXfermode.h
diff --git a/include/client/android/SkAvoidXfermode.h b/include/client/android/SkAvoidXfermode.h
index 34deb8f02fd6b4bf7128e05ee77a18ca77714746..b752d07c403750205784483bccd39bd8bf0d02dd 100644
--- a/include/client/android/SkAvoidXfermode.h
+++ b/include/client/android/SkAvoidXfermode.h
@@ -39,9 +39,14 @@ public:
                 Tolerance near 0: draw only on colors that are nearly identical to the op-color
                 Tolerance near 255: draw on any colors even remotely similar to the op-color
      */
+    static sk_sp<SkXfermode> Make(SkColor opColor, U8CPU tolerance, Mode mode) {
+        return sk_sp<SkXfermode>(new SkAvoidXfermode(opColor, tolerance, mode));
+    }
+#ifdef SK_SUPPORT_LEGACY_XFERMODE_PTR
     static SkAvoidXfermode* Create(SkColor opColor, U8CPU tolerance, Mode mode) {
-        return new SkAvoidXfermode(opColor, tolerance, mode);
+        return (SkAvoidXfermode*)(Make(opColor, tolerance, mode).release());
     }
+#endif
 
     // overrides from SkXfermode
     void xfer32(SkPMColor dst[], const SkPMColor src[], int count,