LibWeb: Add Streams::ReadableStreamDefaultReader::read_all_bytes

Author: https://github.com/shannonbooth
Commit: 3df10d7fb6
Pull-request: https://github.com/SerenityOS/serenity/pull/19404
Reviewed-by: https://github.com/kennethmyhra ✅
Reviewed-by: https://github.com/mattco98 ✅

Userland/Libraries/LibWeb/Streams/ReadableStreamDefaultReader.h

@@ -66,6 +66,8 @@ public:
     virtual ~ReadableStreamDefaultReader() override = default;
 
     WebIDL::ExceptionOr<JS::NonnullGCPtr<JS::Promise>> read();
+
+    WebIDL::ExceptionOr<void> read_all_bytes(ReadLoopReadRequest::SuccessSteps, ReadLoopReadRequest::FailureSteps);
     WebIDL::ExceptionOr<void> release_lock();
 
     SinglyLinkedList<NonnullRefPtr<ReadRequest>>& read_requests() { return m_read_requests; }