Make sp variants for SkData

src/images/SkImageDecoder_libbmp.cpp

Index: src/images/SkImageDecoder_libbmp.cpp
diff --git a/src/images/SkImageDecoder_libbmp.cpp b/src/images/SkImageDecoder_libbmp.cpp
index 4a6f71c82db06a383009343825dca99838a56d5a..b9359bea7a1e169f8b770a0971c38337a0856bec 100644
--- a/src/images/SkImageDecoder_libbmp.cpp
+++ b/src/images/SkImageDecoder_libbmp.cpp
@@ -97,7 +97,7 @@ SkImageDecoder::Result SkBMPImageDecoder::onDecode(SkStream* stream, SkBitmap* b
     // First read the entire stream, so that all of the data can be passed to
     // the BmpDecoderHelper.
 
-    SkAutoTUnref<SkData> data(SkCopyStreamToData(stream));
+    auto data = SkCopyStreamToData(stream);
     if (!data) {
         return kFailure;
     }