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

media/filters/decrypting_video_decoder.h

Index: media/filters/decrypting_video_decoder.h
diff --git a/media/filters/decrypting_video_decoder.h b/media/filters/decrypting_video_decoder.h
index a2a952844d95225a50ed1cb7c04f8ca728149ce6..fda546e8f763f03d8f1ee76d03f02e41efa78bb7 100644
--- a/media/filters/decrypting_video_decoder.h
+++ b/media/filters/decrypting_video_decoder.h
@@ -36,7 +36,7 @@ class MEDIA_EXPORT DecryptingVideoDecoder : public VideoDecoder {
   std::string GetDisplayName() const override;
   void Initialize(const VideoDecoderConfig& config,
                   bool low_delay,
-                  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;
@@ -85,7 +85,7 @@ class MEDIA_EXPORT DecryptingVideoDecoder : public VideoDecoder {
 
   State state_;
 
-  PipelineStatusCB init_cb_;
+  InitCB init_cb_;
   OutputCB output_cb_;
   DecodeCB decode_cb_;
   base::Closure reset_cb_;