Remove MessageLoop methods from Filter interface

media/filters/ffmpeg_audio_decoder.h

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.  Use of this
 // source code is governed by a BSD-style license that can be found in the
 // LICENSE file.
 
 #ifndef MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_
 #define MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_
 
 #include "media/filters/decoder_base.h"
 
 struct AVCodecContext;
 
 namespace media {
 
 // Forward declaration for scoped_ptr_malloc.
 class ScopedPtrAVFree;
 
 class FFmpegAudioDecoder : public DecoderBase<AudioDecoder, Buffer> {
  public:
-  FFmpegAudioDecoder();
+  explicit FFmpegAudioDecoder(MessageLoop* message_loop);
   virtual ~FFmpegAudioDecoder();
 
  protected:
   virtual void DoInitialize(DemuxerStream* demuxer_stream, bool* success,
                             Task* done_cb);
 
   virtual void DoSeek(base::TimeDelta time, Task* done_cb);
 
   virtual void DoDecode(Buffer* input);
 
@@ skipping 14 matching lines @@
   scoped_ptr_malloc<uint8, ScopedPtrAVFree> output_buffer_;
 
   static const size_t kOutputBufferSize;
 
   DISALLOW_COPY_AND_ASSIGN(FFmpegAudioDecoder);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_FFMPEG_AUDIO_DECODER_H_