change SkStreams to work with sk_sp<SkData> instead of SkData*

src/codec/SkCodecImageGenerator.h

 /*
  * 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 "SkCodec.h"
 #include "SkData.h"
 #include "SkImageGenerator.h"
 
 class SkCodecImageGenerator : public SkImageGenerator {
 public:
     /*
      * If this data represents an encoded image that we know how to decode,
      * return an SkCodecImageGenerator.  Otherwise return nullptr.
-     *
-     * Refs the data if an image generator can be returned.  Otherwise does
-     * not affect the data.
      */
-    static SkImageGenerator* NewFromEncodedCodec(SkData* data);
+    static SkImageGenerator* NewFromEncodedCodec(sk_sp<SkData>);
+    static SkImageGenerator* NewFromEncodedCodec(SkData* data) {
+        return NewFromEncodedCodec(sk_ref_sp(data));
+    }
 
 protected:
     SkData* onRefEncodedData(SK_REFENCODEDDATA_CTXPARAM) override;
 
     bool onGetPixels(const SkImageInfo& info, void* pixels, size_t rowBytes, SkPMColor ctable[],
             int* ctableCount) override;
 
     bool onQueryYUV8(SkYUVSizeInfo*, SkYUVColorSpace*) const override;
 
     bool onGetYUV8Planes(const SkYUVSizeInfo&, void* planes[3]) override;
 
 private:
     /*
      * Takes ownership of codec
-     * Refs the data
      */
-    SkCodecImageGenerator(SkCodec* codec, SkData* data);
+    SkCodecImageGenerator(SkCodec* codec, sk_sp<SkData>);
 
     SkAutoTDelete<SkCodec> fCodec;
     sk_sp<SkData> fData;
 
     typedef SkImageGenerator INHERITED;
 };