return and take SkImageGenerator as unique_ptr

BUG=skia:

Change-Id: I4bc11042dd1dbf1eabd40af206027bc65acc3186
Reviewed-on: https://skia-review.googlesource.com/8444
Commit-Queue: Mike Reed <reed@google.com>
Reviewed-by: Matt Sarett <msarett@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
diff --git a/tests/CodecTest.cpp b/tests/CodecTest.cpp
index 8a4d6fc..6423271 100644
--- a/tests/CodecTest.cpp
+++ b/tests/CodecTest.cpp
@@ -436,7 +436,7 @@
         std::unique_ptr<SkStream> stream(GetResourceAsStream(path));
         sk_sp<SkData> fullData(SkData::MakeFromStream(stream.get(), stream->getLength()));
         std::unique_ptr<SkImageGenerator> gen(
-                SkCodecImageGenerator::NewFromEncodedCodec(fullData.get()));
+                SkCodecImageGenerator::MakeFromEncodedCodec(fullData));
         SkBitmap bm;
         bm.allocPixels(info);
         SkAutoLockPixels autoLockPixels(bm);