Add support for cancellation of demuxer reads.

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 68 matching lines @@
   // Enters the end of stream state. After delivering remaining queued buffers
   // only end of stream buffers will be delivered.
   void SetEndOfStream();
 
   // Drops queued buffers and clears end of stream state.
   void FlushBuffers();
 
   // Empties the queues and ignores any additional calls to Read().
   void Stop();
 
+  // Aborts any pending reads.
+  void Abort();
+
   base::TimeDelta duration() const { return duration_; }
 
   // Enables fixes for files with negative timestamps.  Normally all timestamps
   // are rebased against FFmpegDemuxer::start_time() whenever that value is
   // negative.  When this fix is enabled, only AUDIO stream packets will be
   // rebased to time zero, all other stream types will use the muxed timestamp.
   //
   // Further, when no codec delay is present, all AUDIO packets which originally
   // had negative timestamps will be marked for post-decode discard.  When codec
   // delay is present, it is assumed the decoder will handle discard and does
@@ skipping 99 matching lines @@
                 const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
                 const MediaTracksUpdatedCB& media_tracks_updated_cb,
                 const scoped_refptr<MediaLog>& media_log);
   ~FFmpegDemuxer() override;
 
   // Demuxer implementation.
   std::string GetDisplayName() const override;
   void Initialize(DemuxerHost* host,
                   const PipelineStatusCB& status_cb,
                   bool enable_text_tracks) override;
+  void AbortPendingReads() override;
   void Stop() override;
   void StartWaitingForSeek(base::TimeDelta seek_time) override;
   void CancelPendingSeek(base::TimeDelta seek_time) override;
   void Seek(base::TimeDelta time, const PipelineStatusCB& cb) override;
   base::Time GetTimelineOffset() const override;
   DemuxerStream* GetStream(DemuxerStream::Type type) override;
   base::TimeDelta GetStartTime() const override;
   int64_t GetMemoryUsage() const override;
 
   // Calls |encrypted_media_init_data_cb_| with the initialization data
@@ skipping 132 matching lines @@
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<FFmpegDemuxer> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(FFmpegDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_FFMPEG_DEMUXER_H_