Remove RTPVideoHeader::vp9() accessors.

TBR=stefan@webrtc.org

Bug: none
Change-Id: Ia2f728ea3377754a16a0b081e25c4479fe211b3e
Reviewed-on: https://webrtc-review.googlesource.com/93024
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#24243}
diff --git a/modules/video_coding/decoding_state_unittest.cc b/modules/video_coding/decoding_state_unittest.cc
index 740c384..0049ca7 100644
--- a/modules/video_coding/decoding_state_unittest.cc
+++ b/modules/video_coding/decoding_state_unittest.cc
@@ -458,7 +458,8 @@
   packet.dataPtr = data;
   packet.video_header.codec = kVideoCodecVP9;
 
-  RTPVideoHeaderVP9& vp9_hdr = packet.video_header.vp9();
+  auto& vp9_hdr =
+      packet.video_header.video_type_header.emplace<RTPVideoHeaderVP9>();
   vp9_hdr.picture_id = 10;
   vp9_hdr.flexible_mode = true;
 
@@ -501,7 +502,8 @@
   packet.dataPtr = data;
   packet.video_header.codec = kVideoCodecVP9;
 
-  RTPVideoHeaderVP9& vp9_hdr = packet.video_header.vp9();
+  auto& vp9_hdr =
+      packet.video_header.video_type_header.emplace<RTPVideoHeaderVP9>();
   vp9_hdr.picture_id = 10;
   vp9_hdr.flexible_mode = true;
 
@@ -556,7 +558,8 @@
   packet.dataPtr = data;
   packet.video_header.codec = kVideoCodecVP9;
 
-  RTPVideoHeaderVP9& vp9_hdr = packet.video_header.vp9();
+  auto& vp9_hdr =
+      packet.video_header.video_type_header.emplace<RTPVideoHeaderVP9>();
   vp9_hdr.picture_id = 10;
   vp9_hdr.flexible_mode = true;