Reland of Add content type information to encoded images and corresponding rtp extension header

webrtc/test/call_test.cc

Index: webrtc/test/call_test.cc
diff --git a/webrtc/test/call_test.cc b/webrtc/test/call_test.cc
index 5c0b42ca46b462346525c37a18965cb3301bdfa8..6ec3fda86da94503c10db7271cc10b198a303fb7 100644
--- a/webrtc/test/call_test.cc
+++ b/webrtc/test/call_test.cc
@@ -208,6 +208,8 @@ void CallTest::CreateSendConfig(size_t num_video_streams,
     video_send_config_.rtp.extensions.push_back(
         RtpExtension(RtpExtension::kTransportSequenceNumberUri,
                      kTransportSequenceNumberExtensionId));
+    video_send_config_.rtp.extensions.push_back(RtpExtension(
+        RtpExtension::kVideoContentTypeUri, kVideoContentTypeExtensionId));
     FillEncoderConfiguration(num_video_streams, &video_encoder_config_);
 
     for (size_t i = 0; i < num_video_streams; ++i)