Introduce DecodeTimestamp class to make it easier to distiguish presentation and decode timestamps.

media/formats/webm/webm_cluster_parser.h

 // Copyright 2014 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_FORMATS_WEBM_WEBM_CLUSTER_PARSER_H_
 #define MEDIA_FORMATS_WEBM_WEBM_CLUSTER_PARSER_H_
 
 #include <deque>
 #include <map>
 #include <set>
@@ skipping 31 matching lines @@
     Track(int track_num,
           bool is_video,
           base::TimeDelta default_duration,
           const LogCB& log_cb);
     ~Track();
 
     int track_num() const { return track_num_; }
 
     // If a buffer is currently held aside pending duration calculation, returns
     // its decode timestamp. Otherwise, returns kInfiniteDuration().
-    base::TimeDelta GetReadyUpperBound();
+    DecodeTimestamp GetReadyUpperBound();
 
     // Prepares |ready_buffers_| for retrieval. Prior to calling,
-    // |ready_buffers_| must be empty. Moves all |buffers_| with timestamp
-    // before |before_timestamp| to |ready_buffers_|, preserving their order.
-    void ExtractReadyBuffers(const base::TimeDelta before_timestamp);
+    // |ready_buffers_| must be empty. Moves all |buffers_| with decode
+    // timestamp before |before_timestamp| to |ready_buffers_|, preserving their
+    // order.
+    void ExtractReadyBuffers(const DecodeTimestamp before_timestamp);
 
     const BufferQueue& ready_buffers() const { return ready_buffers_; }
 
     // If |last_added_buffer_missing_duration_| is set, updates its duration
     // relative to |buffer|'s timestamp, and adds it to |buffers_| and unsets
     // |last_added_buffer_missing_duration_|. Then, if |buffer| is missing
     // duration, saves |buffer| into |last_added_buffer_missing_duration_|, or
     // otherwise adds |buffer| to |buffers_|.
     bool AddBuffer(const scoped_refptr<StreamParserBuffer>& buffer);
 
@@ skipping 144 matching lines @@
   // Helper method for Get{Audio,Video,Text}Buffers() that recomputes
   // |ready_buffer_upper_bound_| and calls ExtractReadyBuffers() on each track.
   // If |cluster_ended_| is true, first applies duration estimate if needed for
   // |audio_| and |video_| and sets |ready_buffer_upper_bound_| to
   // kInfiniteDuration(). Otherwise, sets |ready_buffer_upper_bound_| to the
   // minimum upper bound across |audio_| and |video_|. (Text tracks can have no
   // buffers missing duration, so they are not involved in calculating the upper
   // bound.)
   // Parse() or Reset() must be called between calls to UpdateReadyBuffers() to
   // clear each track's ready buffers and to reset |ready_buffer_upper_bound_|
-  // to kNoTimestamp().
+  // to kNoDecodeTimestamp().
   void UpdateReadyBuffers();
 
   // Search for the indicated track_num among the text tracks.  Returns NULL
   // if that track num is not a text track.
   Track* FindTextTrack(int track_num);
 
   double timecode_multiplier_;  // Multiplier used to convert timecodes into
                                 // microseconds.
   std::set<int64> ignored_tracks_;
   std::string audio_encryption_key_id_;
@@ skipping 18 matching lines @@
   Track audio_;
   Track video_;
   TextTrackMap text_track_map_;
 
   // Subset of |text_track_map_| maintained by GetTextBuffers(), and cleared by
   // ClearTextTrackReadyBuffers(). Callers of GetTextBuffers() get a const-ref
   // to this member.
   TextBufferQueueMap text_buffers_map_;
 
   // Limits the range of buffers returned by Get{Audio,Video,Text}Buffers() to
-  // this exclusive upper bound. Set to kNoTimestamp(), meaning not yet
-  // calculated, by Reset() and Parse(). If kNoTimestamp(), then
+  // this exclusive upper bound. Set to kNoDecodeTimestamp(), meaning not yet
+  // calculated, by Reset() and Parse(). If kNoDecodeTimestamp(), then
   // Get{Audio,Video,Text}Buffers() will calculate it to be the minimum (decode)
   // timestamp across all tracks' |last_buffer_missing_duration_|, or
   // kInfiniteDuration() if no buffers are currently missing duration.
-  base::TimeDelta ready_buffer_upper_bound_;
+  DecodeTimestamp ready_buffer_upper_bound_;
 
   LogCB log_cb_;
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(WebMClusterParser);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FORMATS_WEBM_WEBM_CLUSTER_PARSER_H_