1 files changed, 9 insertions, 1 deletions
diff --git a/dom/streams/UnderlyingSinkCallbackHelpers.h b/dom/streams/UnderlyingSinkCallbackHelpers.h
index c99c8709ce..0717176aca 100644
--- a/dom/streams/UnderlyingSinkCallbackHelpers.h
+++ b/dom/streams/UnderlyingSinkCallbackHelpers.h
@@ -135,6 +135,10 @@ class UnderlyingSinkAlgorithmsWrapper : public UnderlyingSinkAlgorithmsBase {
     aRetVal.setUndefined();
   }
 
+  MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> WriteCallback(
+      JSContext* aCx, JS::Handle<JS::Value> aChunk,
+      WritableStreamDefaultController& aController, ErrorResult& aRv) final;
+
   MOZ_CAN_RUN_SCRIPT already_AddRefed<Promise> CloseCallback(
       JSContext* aCx, ErrorResult& aRv) final;
 
@@ -142,6 +146,10 @@ class UnderlyingSinkAlgorithmsWrapper : public UnderlyingSinkAlgorithmsBase {
       JSContext* aCx, const Optional<JS::Handle<JS::Value>>& aReason,
       ErrorResult& aRv) final;
 
+  virtual already_AddRefed<Promise> WriteCallbackImpl(
+      JSContext* aCx, JS::Handle<JS::Value> aChunk,
+      WritableStreamDefaultController& aController, ErrorResult& aRv) = 0;
+
   virtual already_AddRefed<Promise> CloseCallbackImpl(JSContext* aCx,
                                                       ErrorResult& aRv) {
     // (closeAlgorithm is optional, give null by default)
@@ -169,7 +177,7 @@ class WritableStreamToOutput final : public UnderlyingSinkAlgorithmsWrapper,
 
   // Streams algorithms
 
-  already_AddRefed<Promise> WriteCallback(
+  already_AddRefed<Promise> WriteCallbackImpl(
       JSContext* aCx, JS::Handle<JS::Value> aChunk,
       WritableStreamDefaultController& aController, ErrorResult& aRv) override;