Move responsibility for RTP header extensions on video receive.

pc/webrtcsession.cc

Index: pc/webrtcsession.cc
diff --git a/pc/webrtcsession.cc b/pc/webrtcsession.cc
index 86015a79facc9cbd8f979abab267921bc146865d..9d8c735933ef45b7548d8f0f243d91b51129f5d1 100644
--- a/pc/webrtcsession.cc
+++ b/pc/webrtcsession.cc
@@ -984,6 +984,21 @@ bool WebRtcSession::PushdownMediaDescription(
       (source == cricket::CS_LOCAL ? local_description() : remote_description())
           ->description();
   RTC_DCHECK(sdesc);
+#if 0
+  if (source == cricket::CS_LOCAL) {
+      const SessionDescription* local_desc = local_description()->description();
+      const ContentInfo* content_info = GetFirstDataContent(local_desc);
+      RTC_DCHECK(IsVideoContent(content_info));
+      const cricket::VideoContentDescription* content_desc =
+          static_cast<const cricket::VideoContentDescription*>(
+              content_info->description);
+      if (content_desc->rtp_header_extensions_set())
+        call_->SetVideoReceiveRtpHeaderExtensions(
+            content_desc->rtp_header_extensions());
+
+      return ch->PushdownLocalDescription(local_description()->description(),
+                                          action, err);
+#endif
   bool all_success = true;
   for (auto* channel : Channels()) {
     // TODO(steveanton): Add support for multiple channels of the same type.