Prototype code that turns any/every flattenable into JSON

src/core/SkFlattenableSerialization.cpp

Index: src/core/SkFlattenableSerialization.cpp
diff --git a/src/core/SkFlattenableSerialization.cpp b/src/core/SkFlattenableSerialization.cpp
index 06e8c1070616c1dc2aa76cf3720389a2abbdef93..704526673da994d35eeaebcb9fc289bf34d3fba6 100644
--- a/src/core/SkFlattenableSerialization.cpp
+++ b/src/core/SkFlattenableSerialization.cpp
@@ -12,7 +12,7 @@
 #include "SkWriteBuffer.h"
 
 SkData* SkValidatingSerializeFlattenable(SkFlattenable* flattenable) {
-    SkWriteBuffer writer;
+    SkBinaryWriteBuffer writer;
     writer.writeFlattenable(flattenable);
     size_t size = writer.bytesWritten();
     auto data = SkData::MakeUninitialized(size);