MSE: Warn when keyframe after track_buffer is significantly in future

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 85ff8d00a919b86461243ef3ec6ad82a8ea201ab..2a3ad9a4d70a4a86ff38f19ce210e149aa83590b 100644
--- a/media/filters/source_buffer_stream.h
+++ b/media/filters/source_buffer_stream.h
@@ -374,6 +374,10 @@ class MEDIA_EXPORT SourceBufferStream {
   // |track_buffer_| is empty, return buffers from |selected_range_|.
   BufferQueue track_buffer_;
 
+  // If there has been no intervening Seek, this will be true if the last
+  // emitted buffer emptied |track_buffer_|.
+  bool just_exhausted_track_buffer_;
+
   // The start time of the current media segment being appended.
   DecodeTimestamp media_segment_start_time_;
 
@@ -420,10 +424,10 @@ class MEDIA_EXPORT SourceBufferStream {
   // Indicates that splice frame generation is enabled.
   const bool splice_frames_enabled_;
 
-  // To prevent log spam, count the number of splice generation warnings and
-  // successes logged.
+  // To prevent log spam, count the number of warnings and successes logged.
   int num_splice_generation_warning_logs_;
   int num_splice_generation_success_logs_;
+  int num_track_buffer_gap_warning_logs_;
 
   DISALLOW_COPY_AND_ASSIGN(SourceBufferStream);
 };