Move pending seek cancellation logic from ChunkDemuxerStream to ChunkDemuxer.

media/filters/chunk_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.
 
 #ifndef MEDIA_FILTERS_CHUNK_DEMUXER_H_
 #define MEDIA_FILTERS_CHUNK_DEMUXER_H_
 
 #include <map>
 #include <string>
 #include <utility>
@@ skipping 44 matching lines @@
   // Demuxer implementation.
   virtual void Initialize(DemuxerHost* host,
                           const PipelineStatusCB& cb) OVERRIDE;
   virtual void Stop(const base::Closure& callback) OVERRIDE;
   virtual void Seek(base::TimeDelta time, const PipelineStatusCB&  cb) OVERRIDE;
   virtual void OnAudioRendererDisabled() OVERRIDE;
   virtual DemuxerStream* GetStream(DemuxerStream::Type type) OVERRIDE;
   virtual base::TimeDelta GetStartTime() const OVERRIDE;
 
   // Methods used by an external object to control this demuxer.
+  //
+  // Indicates that a new Seek() call is on its way. Any pending Reads on the
+  // DemuxerStream objects should be aborted immediately inside this call and
+  // future Read calls should return kAborted until the Seek() call occurs.
+  // This method MUST ALWAYS be called before Seek() is called to signal that
+  // the next Seek() call represents the seek point we actually want to return
+  // data for.
   void StartWaitingForSeek();
+
+  // Indicates that a Seek() call is on its way, but another seek has been
+  // requested that will override the impending Seek() call. Any pending Reads
+  // on the DemuxerStream objects should be aborted immediately inside this call
+  // and future Read calls should return kAborted until the next
+  // StartWaitingForSeek() call. This method also arranges for the next Seek()
+  // call received before a StartWaitingForSeek() call to immediately call its
+  // callback without waiting for any data.
   void CancelPendingSeek();
 
   // Registers a new |id| to use for AppendData() calls. |type| indicates
   // the MIME type for the data that we intend to append for this ID.
   // kOk is returned if the demuxer has enough resources to support another ID
   //    and supports the format indicated by |type|.
   // kNotSupported is returned if |type| is not a supported format.
   // kReachedIdLimit is returned if the demuxer cannot handle another ID right
   //    now.
   Status AddId(const std::string& id, const std::string& type,
@@ skipping 93 matching lines @@
 
   // Sets |duration_| to |new_duration|, sets |user_specified_duration_| to -1
   // and notifies |host_|.
   void UpdateDuration(base::TimeDelta new_duration);
 
   // Returns the ranges representing the buffered data in the demuxer.
   Ranges<base::TimeDelta> GetBufferedRanges() const;
 
   mutable base::Lock lock_;
   State state_;
+  bool cancel_next_seek_;
 
   DemuxerHost* host_;
   base::Closure open_cb_;
   NeedKeyCB need_key_cb_;
   AddTextTrackCB add_text_track_cb_;
   // Callback used to report error strings that can help the web developer
   // figure out what is wrong with the content.
   LogCB log_cb_;
 
   PipelineStatusCB init_cb_;
@@ skipping 22 matching lines @@
   // removed with RemoveID() but can not be re-added (yet).
   std::string source_id_audio_;
   std::string source_id_video_;
 
   DISALLOW_COPY_AND_ASSIGN(ChunkDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_CHUNK_DEMUXER_H_