Reland of Make RTX pt/apt reconfigurable by calling WebRtcVideoChannel2::SetRecvParameters.

webrtc/logging/rtc_event_log/rtc_event_log_parser.cc

Index: webrtc/logging/rtc_event_log/rtc_event_log_parser.cc
diff --git a/webrtc/logging/rtc_event_log/rtc_event_log_parser.cc b/webrtc/logging/rtc_event_log/rtc_event_log_parser.cc
index 3b808b2e43d451fac6915f3aa2a891c5685a2160..c1bf94458dfb3bc2407ef2c2cfb08e80372f7705 100644
--- a/webrtc/logging/rtc_event_log/rtc_event_log_parser.cc
+++ b/webrtc/logging/rtc_event_log/rtc_event_log_parser.cc
@@ -10,8 +10,10 @@
 
 #include "webrtc/logging/rtc_event_log/rtc_event_log_parser.h"
 
+#include <stdint.h>
 #include <string.h>
 
+#include <algorithm>
 #include <fstream>
 #include <istream>
 #include <utility>
@@ -314,17 +316,30 @@ void ParsedRtcEventLog::GetVideoReceiveConfig(
   RTC_CHECK(receiver_config.has_remb());
   config->rtp.remb = receiver_config.remb();
   // Get RTX map.
-  config->rtp.rtx.clear();
+  std::vector<uint32_t> rtx_ssrcs(receiver_config.rtx_map_size());
+  config->rtp.rtx_payload_types.clear();
   for (int i = 0; i < receiver_config.rtx_map_size(); i++) {
     const rtclog::RtxMap& map = receiver_config.rtx_map(i);
     RTC_CHECK(map.has_payload_type());
     RTC_CHECK(map.has_config());
     RTC_CHECK(map.config().has_rtx_ssrc());
+    rtx_ssrcs[i] = map.config().rtx_ssrc();
     RTC_CHECK(map.config().has_rtx_payload_type());
-    webrtc::VideoReceiveStream::Config::Rtp::Rtx rtx_pair;
-    rtx_pair.ssrc = map.config().rtx_ssrc();
-    rtx_pair.payload_type = map.config().rtx_payload_type();
-    config->rtp.rtx.insert(std::make_pair(map.payload_type(), rtx_pair));
+    config->rtp.rtx_payload_types.insert(
+        std::make_pair(map.payload_type(), map.config().rtx_payload_type()));
+  }
+  if (!rtx_ssrcs.empty()) {
+    config->rtp.rtx_ssrc = rtx_ssrcs[0];
+
+    auto pred = [&config](uint32_t ssrc) {
+      return ssrc == config->rtp.rtx_ssrc;
+    };
+    if (!std::all_of(rtx_ssrcs.cbegin(), rtx_ssrcs.cend(), pred)) {
+      LOG(LS_WARNING) << "RtcEventLog protobuf contained different SSRCs for "
+                         "different received RTX payload types. Will only use "
+                         "rtx_ssrc = "
+                      << config->rtp.rtx_ssrc << ".";
+    }
   }
   // Get header extensions.
   GetHeaderExtensions(&config->rtp.extensions,