Fix SourceBufferStream alt-ref frame handling.

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 df32ca39d007822366376c73bb46318bc743b631..1492c9bce28fbc81f3f303194d2050b7d1af7144 100644
--- a/media/filters/source_buffer_stream.h
+++ b/media/filters/source_buffer_stream.h
@@ -125,7 +125,10 @@ class MEDIA_EXPORT SourceBufferStream {
   // end overlaps if necessary.
   // |deleted_buffers| is an output parameter containing candidates for
   // |track_buffer_|.
-  void InsertIntoExistingRange(
+  // Returns true if the buffers were successfully inserted into the existing
+  // range.
+  // Returns false if the buffers being inserted triggered an error.
+  bool InsertIntoExistingRange(
       const RangeList::iterator& range_for_new_buffers_itr,
       const BufferQueue& new_buffers,
       BufferQueue* deleted_buffers);
@@ -297,6 +300,7 @@ class MEDIA_EXPORT SourceBufferStream {
   // The timestamp of the last buffer appended to the media segment, set to
   // kNoTimestamp() if the beginning of the segment.
   base::TimeDelta last_appended_buffer_timestamp_;
+  bool last_appended_buffer_is_keyframe_;
 
   // The decode timestamp on the last buffer returned by the most recent
   // GetNextBuffer() call. Set to kNoTimestamp() if GetNextBuffer() hasn't been