Make VideoDecoderFactory::CreateVideoDecoder private

To ensure CreateVideoDecoder is only used as a fallback when Create is not implemented,
and thus make it safer to migrate VideoDecoderFactory implementations to Create.

Bug: webrtc:15791
Change-Id: Ifb15cf1d303348949ba51a3bb4c91b855a06627f
Reviewed-by: Philip Eliasson <>
Commit-Queue: Danil Chapovalov <>
Cr-Commit-Position: refs/heads/main@{#41777}
diff --git a/api/video_codecs/video_decoder_factory.h b/api/video_codecs/video_decoder_factory.h
index 6048cb2..92a2697 100644
--- a/api/video_codecs/video_decoder_factory.h
+++ b/api/video_codecs/video_decoder_factory.h
@@ -55,8 +55,9 @@
   virtual std::unique_ptr<VideoDecoder> Create(const Environment& env,
                                                const SdpVideoFormat& format);
-  // TODO: - Make private or delete when all callers are
-  // migrated to `Create`.
+ private:
+  // TODO: - Delete when all derived classes implement
+  // `Create`.
   virtual std::unique_ptr<VideoDecoder> CreateVideoDecoder(
       const SdpVideoFormat& format);