message: Remove unused flag ReceiveStreamRtpConfig::transport_cc
  Cr-Commit-Position: refs/heads/main@{#39004}
diff: @@ -40,11 +40,6 @@ class ReceiveStreamInterface {
  // that the value is read on (i.e. packet delivery).
  uint32_t local_ssrc = 0;
  - // Deprecated. This flag has no effect.
  - // TODO(perkj, https://bugs.webrtc.org/14802): Remove this flag once no
  - // projects use it.
  - bool transport_cc = false;
  -
  // RTP header extensions used for the received stream.
  // This value may change mid-stream and must be done on the same thread
  // that the value is read on (i.e. packet delivery).
  