Add PeerConnectionInterface::UpdateCallBitrate.

webrtc/api/peerconnectioninterface.h

Index: webrtc/api/peerconnectioninterface.h
diff --git a/webrtc/api/peerconnectioninterface.h b/webrtc/api/peerconnectioninterface.h
index e96545736257bdbd25b27715bf48c828926d4dcb..3a8c5ab6e013487d002594bb62bf87ffacda78cc 100644
--- a/webrtc/api/peerconnectioninterface.h
+++ b/webrtc/api/peerconnectioninterface.h
@@ -728,6 +728,16 @@ class PeerConnectionInterface : public rtc::RefCountInterface {
   // destroyed, RegisterUMAOberver(nullptr) should be called.
   virtual void RegisterUMAObserver(UMAObserver* observer) = 0;
 
+  // Parameters that are not set will not be changed.
+  struct BitrateUpdate {
+    rtc::Optional<int> min_bitrate_bps;
+    rtc::Optional<int> start_bitrate_bps;
+    rtc::Optional<int> max_bitrate_bps;
+  };
+
+  // Updates the Call level bitrate parameters.
+  virtual void UpdateCallBitrate(const BitrateUpdate&) = 0;
+
   // Returns the current SignalingState.
   virtual SignalingState signaling_state() = 0;
   virtual IceConnectionState ice_connection_state() = 0;