Replace trampolining in FFmpegDemuxer with explicit thread calling convention checks.

media/filters/ffmpeg_demuxer.h

 // Copyright (c) 2012 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.
 
 // Implements the Demuxer interface using FFmpeg's libavformat.  At this time
 // will support demuxing any audio/video format thrown at it.  The streams
 // output mime types audio/x-ffmpeg and video/x-ffmpeg and include an integer
 // key FFmpegCodecID which contains the CodecID enumeration value.  The CodecIDs
 // can be used to create and initialize the corresponding FFmpeg decoder.
 //
@@ skipping 136 matching lines @@
   // about capacity and what buffered data is available.
   void NotifyCapacityAvailable();
   void NotifyBufferingChanged();
 
  private:
   // To allow tests access to privates.
   friend class FFmpegDemuxerTest;
 
   virtual ~FFmpegDemuxer();
 
-  // Carries out initialization on the demuxer thread.
-  void InitializeTask(DemuxerHost* host, const PipelineStatusCB& status_cb);
+  // FFmpeg callbacks during initialization.
   void OnOpenContextDone(const PipelineStatusCB& status_cb, bool result);
   void OnFindStreamInfoDone(const PipelineStatusCB& status_cb, int result);
 
-  // Carries out a seek on the demuxer thread.
-  void SeekTask(base::TimeDelta time, const PipelineStatusCB& cb);
+  // FFmpeg callbacks during seeking.
   void OnSeekFrameDone(const PipelineStatusCB& cb, int result);
 
-  // Carries out demuxing and satisfying stream reads on the demuxer thread.
-  void DemuxTask();
+  // FFmpeg callbacks during reading + helper method to initiate reads.
+  void ReadFrameIfNeeded();
   void OnReadFrameDone(ScopedAVPacket packet, int result);
 
-  // Carries out stopping the demuxer streams on the demuxer thread.
-  void StopTask(const base::Closure& callback);
+  // DataSource callbacks during stopping.
   void OnDataSourceStopped(const base::Closure& callback);
 
-  // Carries out disabling the audio stream on the demuxer thread.
-  void DisableAudioStreamTask();
-
   // Returns true iff any stream has additional capacity. Note that streams can
   // go over capacity depending on how the file is muxed.
   bool StreamsHaveAvailableCapacity();
 
   // Signal all FFmpegDemuxerStreams that the stream has ended.
   void StreamHasEnded();
 
   // Called by |url_protocol_| whenever |data_source_| returns a read error.
   void OnDataSourceError();
 
@@ skipping 54 matching lines @@
   // FFmpegURLProtocol implementation and corresponding glue bits.
   BlockingUrlProtocol url_protocol_;
   scoped_ptr<FFmpegGlue> glue_;
 
   DISALLOW_COPY_AND_ASSIGN(FFmpegDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_FFMPEG_DEMUXER_H_