change flattenable factory to return sk_sp

src/core/SkReadBuffer.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkBitmap.h"
 #include "SkErrorInternals.h"
 #include "SkImage.h"
@@ skipping 338 matching lines @@
         factory = fFactoryArray[index];
     } else {
         factory = (SkFlattenable::Factory)readFunctionPtr();
         if (nullptr == factory) {
             return nullptr; // writer failed to give us the flattenable
         }
     }
 
     // if we get here, factory may still be null, but if that is the case, the
     // failure was ours, not the writer.
-    SkFlattenable* obj = nullptr;
+    sk_sp<SkFlattenable> obj;
     uint32_t sizeRecorded = fReader.readU32();
     if (factory) {
         size_t offset = fReader.offset();
         obj = (*factory)(*this);
         // check that we read the amount we expected
         size_t sizeRead = fReader.offset() - offset;
         if (sizeRecorded != sizeRead) {
             this->validate(false);
             return nullptr;
         }
     } else {
         // we must skip the remaining data
         fReader.skip(sizeRecorded);
     }
-    return obj;
+    return obj.release();
 }
 
 /**
  *  Needs to follow the same pattern as readFlattenable(), but explicitly skip whatever data
  *  has been written.
  */
 void SkReadBuffer::skipFlattenable() {
     if (fFactoryCount > 0) {
         if (0 == fReader.readU32()) {
             return;
         }
     } else {
         if (nullptr == this->readFunctionPtr()) {
             return;
         }
     }
     uint32_t sizeRecorded = fReader.readU32();
     fReader.skip(sizeRecorded);
 }