update callsites for Make image factories

src/core/SkPictureImageGenerator.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkImage_Base.h"
 #include "SkImageGenerator.h"
 #include "SkCanvas.h"
@@ skipping 133 matching lines @@
     if (!surface.get()) {
         return nullptr;
     }
 
     SkMatrix matrix = fMatrix;
     if (subset) {
         matrix.postTranslate(-subset->x(), -subset->y());
     }
     surface->getCanvas()->clear(0); // does NewRenderTarget promise to do this for us?
     surface->getCanvas()->drawPicture(fPicture, &matrix, fPaint.getMaybeNull());
-    SkAutoTUnref<SkImage> image(surface->newImageSnapshot());
-    if (!image.get()) {
+    sk_sp<SkImage> image(surface->makeImageSnapshot());
+    if (!image) {
         return nullptr;
     }
     return SkSafeRef(as_IB(image)->peekTexture());
 }
 #endif