Update AudioRenderer, VideoRenderer, and AudioDecoder Initialize() methods to use PipelineStatusCB.

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 2ee96ff190e5f10529459ad4f23f1bf527e6dc42..5e6077afa17c093ebb3b8bfa7ec496d39d4749a8 100644
--- a/media/filters/ffmpeg_audio_decoder.h
+++ b/media/filters/ffmpeg_audio_decoder.h
@@ -25,7 +25,8 @@ class MEDIA_EXPORT FFmpegAudioDecoder : public AudioDecoder {
   virtual void Flush(const base::Closure& callback) OVERRIDE;
 
   // AudioDecoder implementation.
-  virtual void Initialize(DemuxerStream* stream, const base::Closure& callback,
+  virtual void Initialize(DemuxerStream* stream,
+                          const PipelineStatusCB& callback,
                           const StatisticsCallback& stats_callback) OVERRIDE;
   virtual void Read(const ReadCB& callback) OVERRIDE;
   virtual int bits_per_channel() OVERRIDE;
@@ -35,7 +36,7 @@ class MEDIA_EXPORT FFmpegAudioDecoder : public AudioDecoder {
  private:
   // Methods running on decoder thread.
   void DoInitialize(const scoped_refptr<DemuxerStream>& stream,
-                    const base::Closure& callback,
+                    const PipelineStatusCB& callback,
                     const StatisticsCallback& stats_callback);
   void DoFlush(const base::Closure& callback);
   void DoRead(const ReadCB& callback);