noahric d983c3c9e5 Add SEI to the list of packets counted as keyframe.
It's generated by some encoders between SPS/PPS and an IDR frame, so we should treat it like sps/pps.

BUG=

Review URL: https://codereview.webrtc.org/1664733002

Cr-Commit-Position: refs/heads/master@{#11470}
2016-02-03 11:43:50 +00:00
..
2016-01-04 21:44:16 +00:00