Remove buffer duration calculation from WebMClusterParser and update SourceBufferStream accordingly

media/filters/source_buffer_stream.h

Index: media/filters/source_buffer_stream.h
diff --git a/media/filters/source_buffer_stream.h b/media/filters/source_buffer_stream.h
index db2a92f6b856664bf4600a6c0bd004c430903e32..954ead71a685c6c16b0c0d7f9deb117cba6b3844 100644
--- a/media/filters/source_buffer_stream.h
+++ b/media/filters/source_buffer_stream.h
@@ -34,16 +34,17 @@ class MEDIA_EXPORT SourceBufferStream {
 
   ~SourceBufferStream();
 
+  // Signals that the next buffers appended are part of a new media segment
+  // starting at |media_segment_start_time|.
+  void OnNewMediaSegment(base::TimeDelta media_segment_start_time);
+
   // Add the |buffers| to the SourceBufferStream. Buffers within the queue are
   // expected to be in order, but multiple calls to Append() may add buffers out
   // of order or overlapping. Assumes all buffers within |buffers| are in
   // presentation order and are non-overlapping.
-  // |media_segment_start_time| refers to the starting timestamp for the media
-  // segment to which these buffers belong.
   // Returns true if Append() was successful, false if |buffers| are not added.
   // TODO(vrk): Implement garbage collection. (crbug.com/125070)
-  bool Append(const BufferQueue& buffers,
-              base::TimeDelta media_segment_start_time);
+  bool Append(const BufferQueue& buffers);
 
   // Changes the SourceBufferStream's state so that it will start returning
   // buffers starting from the closest keyframe before |timestamp|.
@@ -103,11 +104,11 @@ class MEDIA_EXPORT SourceBufferStream {
   // the |selected_range_| seeks forward to the next keyframe after (or at) the
   // next buffer timestamp and the overlapped buffers are deleted. But for
   // smooth playback between the old data to the new data's keyframe, some of
-  // these |deleted_buffers| may be temporarily saved into |track_buffer_|.
-  // UpdateTrackBuffer() takes these |deleted_buffers| and decides whether it
+  // these |deleted_buffers_| may be temporarily saved into |track_buffer_|.
+  // UpdateTrackBuffer() takes these |deleted_buffers_| and decides whether it
   // wants to save any buffers into |track_buffer_|.
   // TODO(vrk): This is a little crazy! Ideas for cleanup in crbug.com/129623.
-  void UpdateTrackBuffer(const BufferQueue& deleted_buffers);
+  void UpdateTrackBuffer();
 
   // Checks to see if |range_with_new_buffers_itr| can be merged with the range
   // next to it, and merges them if so.
@@ -158,6 +159,20 @@ class MEDIA_EXPORT SourceBufferStream {
   // EOS buffers for read requests beyond the buffered data.  False initially.
   bool end_of_stream_;
 
+  // True if the next buffer that would have been returned from GetNextBuffer()
+  // was deleted during an Append(). Should never be true outside of an
+  // Append() call.
+  bool deleted_next_buffer_;
+  // Candidates for |track_buffer_|. Should always be empty outside of an
+  // Append() call.
+  BufferQueue deleted_buffers_;
+
+  // The start time of the current media segment being appended.
+  base::TimeDelta media_segment_start_time_;
+
+  // Points to the range containing the current media segment being appended.
+  RangeList::iterator range_for_next_append_;
+
   DISALLOW_COPY_AND_ASSIGN(SourceBufferStream);
 };