Revert of media: Simplify {Audio|Video}Decoder initialization callback.

media/filters/ffmpeg_audio_decoder.cc

Index: media/filters/ffmpeg_audio_decoder.cc
diff --git a/media/filters/ffmpeg_audio_decoder.cc b/media/filters/ffmpeg_audio_decoder.cc
index 22a907b621beeb0862f49572001d6cad3da13d74..2f8bf1b87f796396c44aa820d3f9b8f337b8cb26 100644
--- a/media/filters/ffmpeg_audio_decoder.cc
+++ b/media/filters/ffmpeg_audio_decoder.cc
@@ -147,7 +147,7 @@
 }
 
 void FFmpegAudioDecoder::Initialize(const AudioDecoderConfig& config,
-                                    const InitCB& init_cb,
+                                    const PipelineStatusCB& status_cb,
                                     const OutputCB& output_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!config.is_encrypted());
@@ -155,17 +155,17 @@
   FFmpegGlue::InitializeFFmpeg();
 
   config_ = config;
-  InitCB bound_init_cb = BindToCurrentLoop(init_cb);
+  PipelineStatusCB initialize_cb = BindToCurrentLoop(status_cb);
 
   if (!config.IsValidConfig() || !ConfigureDecoder()) {
-    bound_init_cb.Run(false);
+    initialize_cb.Run(DECODER_ERROR_NOT_SUPPORTED);
     return;
   }
 
   // Success!
   output_cb_ = BindToCurrentLoop(output_cb);
   state_ = kNormal;
-  bound_init_cb.Run(true);
+  initialize_cb.Run(PIPELINE_OK);
 }
 
 void FFmpegAudioDecoder::Decode(const scoped_refptr<DecoderBuffer>& buffer,