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

tools/skdiff_utils.cpp

Index: tools/skdiff_utils.cpp
diff --git a/tools/skdiff_utils.cpp b/tools/skdiff_utils.cpp
index 3a377336829ecaf6ff566ac76fd5b6e8d4e78c44..609d75d265a61fa983ffdbbae3305d166f82e9d9 100644
--- a/tools/skdiff_utils.cpp
+++ b/tools/skdiff_utils.cpp
@@ -33,7 +33,7 @@ sk_sp<SkData> read_file(const char* file_path) {
     return data;
 }
 
-bool get_bitmap(SkData* fileBits, DiffResource& resource, bool sizeOnly) {
+bool get_bitmap(sk_sp<SkData> fileBits, DiffResource& resource, bool sizeOnly) {
     SkAutoTDelete<SkCodec> codec(SkCodec::NewFromData(fileBits));
     if (!codec) {
         SkDebugf("ERROR: could not create codec for <%s>\n", resource.fFullPath.c_str());