Remove WebRTC-videocontenttypeextension field trial completely

webrtc/video/video_send_stream.cc

Index: webrtc/video/video_send_stream.cc
diff --git a/webrtc/video/video_send_stream.cc b/webrtc/video/video_send_stream.cc
index 253d11cb798ac199b70704afe3151d4bd95454fd..c9788dfac19ea48cd2c179d336be2d95cf51480a 100644
--- a/webrtc/video/video_send_stream.cc
+++ b/webrtc/video/video_send_stream.cc
@@ -742,10 +742,6 @@ VideoSendStreamImpl::VideoSendStreamImpl(
     RTC_DCHECK_GE(id, 1);
     RTC_DCHECK_LE(id, 14);
     RTC_DCHECK(RtpExtension::IsSupportedForVideo(extension));
-    if (StringToRtpExtensionType(extension) == kRtpExtensionVideoContentType &&
-        !field_trial::IsEnabled("WebRTC-VideoContentTypeExtension")) {
-      continue;
-    }
     for (RtpRtcp* rtp_rtcp : rtp_rtcp_modules_) {
       RTC_CHECK_EQ(0, rtp_rtcp->RegisterSendRtpHeaderExtension(
                           StringToRtpExtensionType(extension), id));