[MSE] Fix GC with media_time past the last appended buffer timestamp

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 deec40970ba53217343f32302db684e628dff651..91a75dcb2ef55c7f807aacb94462dc3823ba445d 100644
--- a/media/filters/source_buffer_stream.h
+++ b/media/filters/source_buffer_stream.h
@@ -407,6 +407,7 @@ class MEDIA_EXPORT SourceBufferStream {
   // The timestamp of the last buffer appended to the media segment, set to
   // kNoDecodeTimestamp() if the beginning of the segment.
   DecodeTimestamp last_appended_buffer_timestamp_;
+  base::TimeDelta last_appended_buffer_duration_;
   bool last_appended_buffer_is_keyframe_ = false;
 
   // The decode timestamp on the last buffer returned by the most recent