Use sk_sp text blob APIs

gm/textblobtransforms.cpp

Index: gm/textblobtransforms.cpp
diff --git a/gm/textblobtransforms.cpp b/gm/textblobtransforms.cpp
index 537ddb161666c5655b6cc34f6b16c88b0dcb4f6a..54c6b4417cacdca3b0c85be99c9aa95ca9b0a512 100644
--- a/gm/textblobtransforms.cpp
+++ b/gm/textblobtransforms.cpp
@@ -49,7 +49,7 @@ protected:
         sk_tool_utils::add_to_text_blob(&builder, text, paint, xOffset, -yOffset - 10);
 
         // build
-        fBlob.reset(builder.build());
+        fBlob = builder.make();
     }
 
     SkString onShortName() override {
@@ -158,7 +158,7 @@ protected:
     }
 
 private:
-    SkAutoTUnref<const SkTextBlob> fBlob;
+    sk_sp<SkTextBlob> fBlob;
 
     static constexpr int kWidth = 1000;
     static constexpr int kHeight = 1200;