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

tests/PDFGlyphsToUnicodeTest.cpp

Index: tests/PDFGlyphsToUnicodeTest.cpp
diff --git a/tests/PDFGlyphsToUnicodeTest.cpp b/tests/PDFGlyphsToUnicodeTest.cpp
index f65ee3e3c7239e72376dc16f533063359bf3c3a9..b3ee2d86f2cf20a83a84a97f877d76b255fb8439 100644
--- a/tests/PDFGlyphsToUnicodeTest.cpp
+++ b/tests/PDFGlyphsToUnicodeTest.cpp
@@ -15,7 +15,7 @@ static const int kMaximumGlyphCount = SK_MaxU16 + 1;
 
 static bool stream_equals(const SkDynamicMemoryWStream& stream, size_t offset,
                           const char* buffer, size_t len) {
-    sk_sp<SkData> data(stream.copyToData());
+    sk_sp<SkData> data = stream.snapshotAsData();
     if (offset + len > data->size()) {
         return false;
     }