[serializer] change internal field callbacks to take data pointer.

src/snapshot/partial-serializer.cc

Index: src/snapshot/partial-serializer.cc
diff --git a/src/snapshot/partial-serializer.cc b/src/snapshot/partial-serializer.cc
index a141aac19339b9fa32da323ca755122b5ed7e7e9..b78a1edbd0647f52079a4a3ee1c4b922ad334c5f 100644
--- a/src/snapshot/partial-serializer.cc
+++ b/src/snapshot/partial-serializer.cc
@@ -103,7 +103,7 @@ void PartialSerializer::SerializeObject(HeapObject* obj, HowToCode how_to_code,
   if (obj->IsJSObject()) {
     JSObject* jsobj = JSObject::cast(obj);
     if (jsobj->GetInternalFieldCount() > 0) {
-      DCHECK_NOT_NULL(serialize_internal_fields_);
+      DCHECK_NOT_NULL(serialize_internal_fields_.callback);
       internal_field_holders_.Add(jsobj);
     }
   }
@@ -132,7 +132,7 @@ void PartialSerializer::SerializeInternalFields() {
   DisallowHeapAllocation no_gc;
   DisallowJavascriptExecution no_js(isolate());
   DisallowCompilation no_compile(isolate());
-  DCHECK_NOT_NULL(serialize_internal_fields_);
+  DCHECK_NOT_NULL(serialize_internal_fields_.callback);
   sink_.Put(kInternalFieldsData, "internal fields data");
   while (internal_field_holders_.length() > 0) {
     HandleScope scope(isolate());
@@ -142,7 +142,8 @@ void PartialSerializer::SerializeInternalFields() {
     int internal_fields_count = obj->GetInternalFieldCount();
     for (int i = 0; i < internal_fields_count; i++) {
       if (obj->GetInternalField(i)->IsHeapObject()) continue;
-      StartupData data = serialize_internal_fields_(v8::Utils::ToLocal(obj), i);
+      StartupData data = serialize_internal_fields_.callback(
+          v8::Utils::ToLocal(obj), i, serialize_internal_fields_.data);
       sink_.Put(kNewObject + reference.space(), "internal field holder");
       PutBackReference(*obj, reference);
       sink_.PutInt(i, "internal field index");