Fix SPS/PPS insertion logic in MP4StreamParser.

media/formats/mp4/mp4_stream_parser_unittest.cc

Index: media/formats/mp4/mp4_stream_parser_unittest.cc
diff --git a/media/formats/mp4/mp4_stream_parser_unittest.cc b/media/formats/mp4/mp4_stream_parser_unittest.cc
index 6f58c6a99dc9c3704eda68646856a026d2846672..69253f521f933985e5007395212d11e9236708f8 100644
--- a/media/formats/mp4/mp4_stream_parser_unittest.cc
+++ b/media/formats/mp4/mp4_stream_parser_unittest.cc
@@ -214,6 +214,12 @@ TEST_F(MP4StreamParserTest, MissingSampleAuxInfo) {
   ParseMP4File("bear-1280x720-a_frag-cenc_missing-saiz-saio.mp4", 512);
 }
 
+// Test a file where all video samples start with an Access Unit
+// Delimiter (AUD) NALU.
+TEST_F(MP4StreamParserTest, VideoSamplesStartWithAUDs) {
+  ParseMP4File("bear-1280x720-av_with-aud-nalus_frag.mp4", 512);
+}
+
 // TODO(strobe): Create and test media which uses CENC auxiliary info stored
 // inside a private box