Use sk_sp text blob APIs

src/utils/SkTextBox.cpp

 /*
  * Copyright 2006 The Android Open Source Project
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkTextBox.h"
 #include "SkUtils.h"
 
@@ skipping 274 matching lines @@
 
     void operator()(const char text[], size_t length, SkScalar x, SkScalar y,
                     const SkPaint& paint) override {
         SkPaint p(paint);
         p.setTextEncoding(SkPaint::kGlyphID_TextEncoding);
         const int count = paint.countText(text, length);
         paint.textToGlyphs(text, length, fBuilder.allocRun(p, count, x, y).glyphs);
     }
 };
 
-SkTextBlob* SkTextBox::snapshotTextBlob(SkScalar* computedBottom) const {
+sk_sp<SkTextBlob> SkTextBox::snapshotTextBlob(SkScalar* computedBottom) const {
     TextBlobVisitor visitor;
     SkScalar newB = this->visit(visitor, fText, fLen, *fPaint);
     if (computedBottom) {
         *computedBottom = newB;
     }
-    return (SkTextBlob*)visitor.fBuilder.build();
+    return visitor.fBuilder.make();
 }