Remove MessageLoop methods from Filter interface

media/filters/ffmpeg_demuxer.h

Index: media/filters/ffmpeg_demuxer.h
diff --git a/media/filters/ffmpeg_demuxer.h b/media/filters/ffmpeg_demuxer.h
index e5355203597fc52c773f9924157d05320c187476..21235638e49274a5fa89c3dfbc9537673c84097f 100644
--- a/media/filters/ffmpeg_demuxer.h
+++ b/media/filters/ffmpeg_demuxer.h
@@ -121,7 +121,7 @@ class FFmpegDemuxerStream : public DemuxerStream, public AVStreamProvider {
 class FFmpegDemuxer : public Demuxer,
                       public FFmpegURLProtocol {
  public:
-  FFmpegDemuxer();
+  explicit FFmpegDemuxer(MessageLoop* message_loop);
   virtual ~FFmpegDemuxer();
 
   // Posts a task to perform additional demuxing.
@@ -144,6 +144,9 @@ class FFmpegDemuxer : public Demuxer,
   virtual bool GetSize(int64* size_out);
   virtual bool IsStreaming();
 
+  // Provide access to FFmpegDemuxerStream.
+  MessageLoop* message_loop();
+
  private:
   // Only allow a factory to create this class.
   friend class MockFFmpegDemuxer;
@@ -187,6 +190,8 @@ class FFmpegDemuxer : public Demuxer,
   // Signal that read has completed, and |size| bytes have been read.
   virtual void SignalReadCompleted(size_t size);
 
+  MessageLoop* message_loop_;
+
   // FFmpeg context handle.
   AVFormatContext* format_context_;