use unique_ptr for codec factories

Will need guards for android (at least)

Bug: skia:
Change-Id: I2bb8e656997984489ef1f2e41cd3d301c4e7b947
Reviewed-on: https://skia-review.googlesource.com/26040
Reviewed-by: Mike Klein <mtklein@chromium.org>
Commit-Queue: Mike Reed <reed@google.com>
diff --git a/src/codec/SkGifCodec.h b/src/codec/SkGifCodec.h
index 6ecd419..89c84bd 100644
--- a/src/codec/SkGifCodec.h
+++ b/src/codec/SkGifCodec.h
@@ -29,7 +29,7 @@
      * Assumes IsGif was called and returned true
      * Reads enough of the stream to determine the image format
      */
-    static SkCodec* NewFromStream(SkStream*, Result*);
+    static std::unique_ptr<SkCodec> MakeFromStream(std::unique_ptr<SkStream>, Result*);
 
     // Callback for SkGifImageReader when a row is available.
     bool haveDecodedRow(int frameIndex, const unsigned char* rowBegin,