Reland of Periodically update codec bit/frame rate settings.

webrtc/modules/video_coding/media_optimization.cc

Index: webrtc/modules/video_coding/media_optimization.cc
diff --git a/webrtc/modules/video_coding/media_optimization.cc b/webrtc/modules/video_coding/media_optimization.cc
index ccd23f6ae4729214639e45ed786979f36caf5455..f0cbd62c9bf669d35578ea5f5f44284f5ffb8bc8 100644
--- a/webrtc/modules/video_coding/media_optimization.cc
+++ b/webrtc/modules/video_coding/media_optimization.cc
@@ -118,7 +118,13 @@ uint32_t MediaOptimization::SetTargetRates(uint32_t target_bitrate) {
   // Update encoding rates following protection settings.
   float target_video_bitrate_kbps =
       static_cast<float>(video_target_bitrate_) / 1000.0f;
-  frame_dropper_->SetRates(target_video_bitrate_kbps, incoming_frame_rate_);
+  float framerate = incoming_frame_rate_;
+  if (framerate == 0.0) {
+    // No framerate estimate available, use configured max framerate instead.
+    framerate = user_frame_rate_;
+  }
+
+  frame_dropper_->SetRates(target_video_bitrate_kbps, framerate);
 
   return video_target_bitrate_;
 }