Delete media transport integration.

MediaTransport is deprecated and the code is unused.

No-Try: True
Bug: webrtc:9719
Change-Id: I5b864c1e74bf04df16c15f51b8fac3d407331dcd
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/160620
Commit-Queue: Bjorn Mellem <mellem@webrtc.org>
Reviewed-by: Niels Moller <nisse@webrtc.org>
Reviewed-by: Gustaf Ullberg <gustaf@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Reviewed-by: Steve Anton <steveanton@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29923}
diff --git a/api/peer_connection_interface.h b/api/peer_connection_interface.h
index 5047eef..d118e52 100644
--- a/api/peer_connection_interface.h
+++ b/api/peer_connection_interface.h
@@ -619,19 +619,12 @@
     // correctly. This flag will be deprecated soon. Do not rely on it.
     bool active_reset_srtp_params = false;
 
-    // If MediaTransportFactory is provided in PeerConnectionFactory, this flag
-    // informs PeerConnection that it should use the MediaTransportInterface for
-    // media (audio/video). It's invalid to set it to |true| if the
-    // MediaTransportFactory wasn't provided.
+    // DEPRECATED.  Do not use.  This option is ignored by peer connection.
+    // TODO(webrtc:9719):  Delete this option.
     bool use_media_transport = false;
 
-    // If MediaTransportFactory is provided in PeerConnectionFactory, this flag
-    // informs PeerConnection that it should use the MediaTransportInterface for
-    // data channels.  It's invalid to set it to |true| if the
-    // MediaTransportFactory wasn't provided.  Data channels over media
-    // transport are not compatible with RTP or SCTP data channels.  Setting
-    // both |use_media_transport_for_data_channels| and
-    // |enable_rtp_data_channel| is invalid.
+    // DEPRECATED.  Do not use.  This option is ignored by peer connection.
+    // TODO(webrtc:9719):  Delete this option.
     bool use_media_transport_for_data_channels = false;
 
     // If MediaTransportFactory is provided in PeerConnectionFactory, this flag