Create video and audio decoder threads on demand.

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 edf93345bdec109c5f261c7e7b3ca2b235cd7004..4b24797726e4ae89b861407a5d0ab49c45c96f6f 100644
--- a/media/filters/ffmpeg_audio_decoder.h
+++ b/media/filters/ffmpeg_audio_decoder.h
@@ -7,6 +7,7 @@
 
 #include <list>
 
+#include "base/callback.h"
 #include "base/message_loop.h"
 #include "media/base/audio_decoder.h"
 
@@ -15,10 +16,11 @@ struct AVCodecContext;
 namespace media {
 
 class DataBuffer;
+class MessageLoopFactory;

[Ami GONE FROM CHROMIUM, 2012/03/09 16:15:06]

Unnecessary

[tommi (sloooow) - chröme, 2012/03/11 18:49:36]

Done.

 
 class MEDIA_EXPORT FFmpegAudioDecoder : public AudioDecoder {
  public:
-  explicit FFmpegAudioDecoder(MessageLoop* message_loop);
+  FFmpegAudioDecoder(const base::Callback<MessageLoop*()>& message_loop_cb);
   virtual ~FFmpegAudioDecoder();
 
   // AudioDecoder implementation.
@@ -55,6 +57,7 @@ class MEDIA_EXPORT FFmpegAudioDecoder : public AudioDecoder {
   // Delivers decoded samples to |read_cb_| and resets the callback.
   void DeliverSamples(const scoped_refptr<Buffer>& samples);
 
+  base::Callback<MessageLoop*()> message_loop_cb_;
   MessageLoop* message_loop_;
 
   scoped_refptr<DemuxerStream> demuxer_stream_;