Reland of H.264 packetization mode 0 (try 3)

webrtc/video/payload_router.cc

Index: webrtc/video/payload_router.cc
diff --git a/webrtc/video/payload_router.cc b/webrtc/video/payload_router.cc
index 6c8e36f72f448919ff8bde5411f603f891821f6f..8b29e818f0eff00e21eb77b594971451caad567b 100644
--- a/webrtc/video/payload_router.cc
+++ b/webrtc/video/payload_router.cc
@@ -75,6 +75,8 @@ void CopyCodecSpecific(const CodecSpecificInfo* info, RTPVideoHeader* rtp) {
     }
     case kVideoCodecH264:
       rtp->codec = kRtpVideoH264;
+      rtp->codecHeader.H264.packetization_mode =
+          info->codecSpecific.H264.packetization_mode;
       return;
     case kVideoCodecGeneric:
       rtp->codec = kRtpVideoGeneric;