Probing: Add support for exponential startup probing

webrtc/modules/bitrate_controller/bitrate_controller_impl.h

Index: webrtc/modules/bitrate_controller/bitrate_controller_impl.h
diff --git a/webrtc/modules/bitrate_controller/bitrate_controller_impl.h b/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
index e5f595d09e7bb798ddf48fac527011f3cba788a8..0cd7e40a5e3d2752f0dd71b820cf633696ca6e9d 100644
--- a/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
+++ b/webrtc/modules/bitrate_controller/bitrate_controller_impl.h
@@ -52,7 +52,6 @@ class BitrateControllerImpl : public BitrateController {
                      int min_bitrate_bps,
                      int max_bitrate_bps) override;
 
-  void UpdateDelayBasedEstimate(uint32_t bitrate_bps) override;
 
   void SetReservedBitrate(uint32_t reserved_bitrate_bps) override;
 
@@ -61,7 +60,10 @@ class BitrateControllerImpl : public BitrateController {
                             uint8_t* fraction_loss,
                             int64_t* rtt) override;
 
-  void UpdateProbeBitrate(uint32_t bitrate_bps) override;
+  // RemoteBitrateObserver overrides.
+  void OnReceiveBitrateChanged(const std::vector<uint32_t>& ssrcs,
+                               uint32_t bitrate_bps) override;
+  void OnProbeBitrate(uint32_t bitrate_bps) override;
 
   int64_t TimeUntilNextProcess() override;
   void Process() override;
@@ -70,7 +72,7 @@ class BitrateControllerImpl : public BitrateController {
   class RtcpBandwidthObserverImpl;
 
   // Called by BitrateObserver's direct from the RTCP module.
-  void OnReceivedEstimatedBitrate(uint32_t bitrate);
+  void OnReceiverEstimatedBitrate(uint32_t bitrate);
 
   void OnReceivedRtcpReceiverReport(uint8_t fraction_loss,
                                     int64_t rtt,