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

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2333713002

Review-Url: https://codereview.chromium.org/2333713002
diff --git a/tools/viewer/ImageSlide.cpp b/tools/viewer/ImageSlide.cpp
index 7dcee5d..78fb17b 100644
--- a/tools/viewer/ImageSlide.cpp
+++ b/tools/viewer/ImageSlide.cpp
@@ -37,7 +37,7 @@
 
 void ImageSlide::load(SkScalar, SkScalar) {
     sk_sp<SkData> encoded = SkData::MakeFromFileName(fPath.c_str());
-    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(encoded.get()));
+    SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(encoded));
     if (!codec) {
         return;
     }