Add PeerConnectionInterface::UpdateCallBitrate.

webrtc/pc/peerconnection.cc

Index: webrtc/pc/peerconnection.cc
diff --git a/webrtc/pc/peerconnection.cc b/webrtc/pc/peerconnection.cc
index a3981039e6cfe89554092b4c14d7f2f7b0f175e4..900afc932074b9f82410c2a5a3b0273be79b18e2 100644
--- a/webrtc/pc/peerconnection.cc
+++ b/webrtc/pc/peerconnection.cc
@@ -1235,6 +1235,19 @@ void PeerConnection::RegisterUMAObserver(UMAObserver* observer) {
   }
 }
 
+void PeerConnection::SetBitrate(const BitrateParameters& bitrate) {
+  factory_->worker_thread()->Invoke<void>(RTC_FROM_HERE, [this, &bitrate]() {
+    Call::Config::BitrateConfigMask mask;
+    mask.min_bitrate_bps = bitrate.min_bitrate_bps;
+    mask.start_bitrate_bps = bitrate.start_bitrate_bps;
+    mask.max_bitrate_bps = bitrate.max_bitrate_bps;
+
+    RTC_DCHECK(media_controller_);
+    Call* call = media_controller_->call_w();
+    call->SetBitrateConfigMask(mask);
+  });
+}
+
 bool PeerConnection::StartRtcEventLog(rtc::PlatformFile file,
                                       int64_t max_size_bytes) {
   return factory_->worker_thread()->Invoke<bool>(