media: Reland "Simplify {Audio|Video}Decoder initialization callback."

media/filters/ffmpeg_audio_decoder.h

Index: media/filters/ffmpeg_audio_decoder.h
diff --git a/media/filters/ffmpeg_audio_decoder.h b/media/filters/ffmpeg_audio_decoder.h
index c9429f989de9b0dbbce612d96be77186b846d4e9..2446ce59a481acf842ab09b420226dc5c5bb6dc4 100644
--- a/media/filters/ffmpeg_audio_decoder.h
+++ b/media/filters/ffmpeg_audio_decoder.h
@@ -38,7 +38,7 @@ class MEDIA_EXPORT FFmpegAudioDecoder : public AudioDecoder {
   // AudioDecoder implementation.
   std::string GetDisplayName() const override;
   void Initialize(const AudioDecoderConfig& config,
-                  const PipelineStatusCB& status_cb,
+                  const InitCB& init_cb,
                   const OutputCB& output_cb) override;
   void Decode(const scoped_refptr<DecoderBuffer>& buffer,
               const DecodeCB& decode_cb) override;