Updated structures and functions for setting the max bitrate limit to take rtc::Optional<int>

webrtc/media/engine/simulcast.cc

Index: webrtc/media/engine/simulcast.cc
diff --git a/webrtc/media/engine/simulcast.cc b/webrtc/media/engine/simulcast.cc
index cbcf245efdde2ff2be6522518d6fa792b0bb09dc..71f312b2545d6013f9db2c64a9183d30bdfd3505 100644
--- a/webrtc/media/engine/simulcast.cc
+++ b/webrtc/media/engine/simulcast.cc
@@ -171,7 +171,7 @@ std::vector<webrtc::VideoStream> GetSimulcastConfig(
     size_t max_streams,
     int width,
     int height,
-    int max_bitrate_bps,
+    rtc::Optional<int> max_bitrate_bps,
     int max_qp,
     int max_framerate) {
   size_t simulcast_layers = FindSimulcastMaxLayers(width, height);
@@ -216,9 +216,11 @@ std::vector<webrtc::VideoStream> GetSimulcastConfig(
   }
 
   // Spend additional bits to boost the max stream.
-  int bitrate_left_bps = max_bitrate_bps - GetTotalMaxBitrateBps(streams);
-  if (bitrate_left_bps > 0) {
-    streams.back().max_bitrate_bps += bitrate_left_bps;
+  if (max_bitrate_bps) {
+    int bitrate_left_bps = *max_bitrate_bps - GetTotalMaxBitrateBps(streams);
+    if (bitrate_left_bps > 0) {
+      streams.back().max_bitrate_bps += bitrate_left_bps;
+    }
   }
 
   return streams;