Add ability to set max probing bitrate via GoogCcNetworkController

Bug: webrtc:10223
Change-Id: I8e9ee0cd333634e7d0b53d3d446a580374cc88b4
Reviewed-on: https://webrtc-review.googlesource.com/c/120342
Commit-Queue: Erik Språng <sprang@webrtc.org>
Reviewed-by: Sebastian Jansson <srte@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26452}

rtc_base/experiments/rate_control_settings.h

diff --git a/rtc_base/experiments/rate_control_settings.h b/rtc_base/experiments/rate_control_settings.h
index ff071d8..cbc2e69 100644
--- a/rtc_base/experiments/rate_control_settings.h
+++ b/rtc_base/experiments/rate_control_settings.h
@@ -44,6 +44,8 @@
   double GetSimulcastVideoHysteresisFactor() const;
   double GetSimulcastScreenshareHysteresisFactor() const;
 
+  bool TriggerProbeOnMaxAllocatedBitrateChange() const;
+
  private:
   explicit RateControlSettings(
       const WebRtcKeyValueConfig* const key_value_config);
@@ -56,6 +58,7 @@
   FieldTrialParameter<bool> trust_vp9_;
   FieldTrialParameter<double> video_hysteresis_;
   FieldTrialParameter<double> screenshare_hysteresis_;
+  FieldTrialParameter<bool> probe_max_allocation_;
 };
 
 }  // namespace webrtc