Add PeerConnectionInterface::UpdateCallBitrate.

webrtc/call/call.cc

Index: webrtc/call/call.cc
diff --git a/webrtc/call/call.cc b/webrtc/call/call.cc
index e9838d9baad0acdadde8f33ddc12bb863068cc92..7c3e230b1969e3fd24c1c1feb36d3b66ae9c54a1 100644
--- a/webrtc/call/call.cc
+++ b/webrtc/call/call.cc
@@ -180,6 +180,9 @@ class Call : public webrtc::Call,
   void SetBitrateConfig(
       const webrtc::Call::Config::BitrateConfig& bitrate_config) override;
 
+  void UpdateBitrateConfig(
+      const webrtc::Call::Config::BitrateConfigMask& bitrate_config) override;
+
   void SignalChannelNetworkState(MediaType media, NetworkState state) override;
 
   void OnTransportOverheadChanged(MediaType media,
@@ -922,6 +925,23 @@ void Call::SetBitrateConfig(
       bitrate_config.max_bitrate_bps);
 }
 
+void Call::UpdateBitrateConfig(
+    const webrtc::Call::Config::BitrateConfigMask& mask) {
+  TRACE_EVENT0("webrtc", "Call::UpdateBitrateConfig");
+  RTC_DCHECK(configuration_thread_checker_.CalledOnValidThread());
+
+  const Config::BitrateConfig& current_config = config_.bitrate_config;
+  Config::BitrateConfig new_config;
+  new_config.min_bitrate_bps =
+      mask.min_bitrate_bps.value_or(current_config.min_bitrate_bps);
+  new_config.start_bitrate_bps =
+      mask.start_bitrate_bps.value_or(current_config.start_bitrate_bps);
+  new_config.max_bitrate_bps =
+      mask.max_bitrate_bps.value_or(current_config.max_bitrate_bps);
+
+  SetBitrateConfig(new_config);
+}
+
 void Call::SignalChannelNetworkState(MediaType media, NetworkState state) {
   RTC_DCHECK(configuration_thread_checker_.CalledOnValidThread());
   switch (media) {