Revert of Propagate probing cluster id to SendTimeHistory.

webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h

Index: webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
diff --git a/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h b/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
index 79e767765d1f28b692de5398c81f0e88f4cbecdc..282483b0953fda31fd14b9877924dcf75fc78e95 100644
--- a/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
+++ b/webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h
@@ -245,44 +245,32 @@
 
 struct PacketInfo {
   PacketInfo(int64_t arrival_time_ms, uint16_t sequence_number)
-      : PacketInfo(-1,
-                   arrival_time_ms,
-                   -1,
-                   sequence_number,
-                   0,
-                   false,
-                   kNotAProbe) {}
+      : PacketInfo(-1, arrival_time_ms, -1, sequence_number, 0, false) {}
 
   PacketInfo(int64_t arrival_time_ms,
              int64_t send_time_ms,
              uint16_t sequence_number,
              size_t payload_size,
-             bool was_paced,
-             int probe_cluster_id)
+             bool was_paced)
       : PacketInfo(-1,
                    arrival_time_ms,
                    send_time_ms,
                    sequence_number,
                    payload_size,
-                   was_paced,
-                   probe_cluster_id) {}
+                   was_paced) {}
 
   PacketInfo(int64_t creation_time_ms,
              int64_t arrival_time_ms,
              int64_t send_time_ms,
              uint16_t sequence_number,
              size_t payload_size,
-             bool was_paced,
-             int probe_cluster_id)
+             bool was_paced)
       : creation_time_ms(creation_time_ms),
         arrival_time_ms(arrival_time_ms),
         send_time_ms(send_time_ms),
         sequence_number(sequence_number),
         payload_size(payload_size),
-        was_paced(was_paced),
-        probe_cluster_id(probe_cluster_id) {}
-
-  static constexpr int kNotAProbe = -1;
+        was_paced(was_paced) {}
 
   // Time corresponding to when this object was created.
   int64_t creation_time_ms;
@@ -299,8 +287,6 @@
   size_t payload_size;
   // True if the packet was paced out by the pacer.
   bool was_paced;
-  // Which probing cluster this packets belongs to.
-  int probe_cluster_id;
 };
 
 class TransportFeedbackObserver {
@@ -312,8 +298,7 @@
   // must be set to 0.
   virtual void AddPacket(uint16_t sequence_number,
                          size_t length,
-                         bool was_paced,
-                         int probe_cluster_id) = 0;
+                         bool was_paced) = 0;
 
   virtual void OnTransportFeedback(const rtcp::TransportFeedback& feedback) = 0;
 };