Reland "Wire up send-side bandwidth estimation."

webrtc/video/video_loopback.cc

Index: webrtc/video/video_loopback.cc
diff --git a/webrtc/video/video_loopback.cc b/webrtc/video/video_loopback.cc
index c5e9254c087ff4a106903885be2797e56551657e..0dceea82e6ea45e5f85bbfa7e5844036ac7a9956 100644
--- a/webrtc/video/video_loopback.cc
+++ b/webrtc/video/video_loopback.cc
@@ -140,6 +140,8 @@ int DurationSecs() {
   return static_cast<int>(FLAGS_duration);
 }
 
+DEFINE_bool(send_side_bwe, true, "Use send-side bandwidth estimation");
+
 }  // namespace flags
 
 void Loopback() {
@@ -158,19 +160,13 @@ void Loopback() {
   std::string clip = flags::Clip();
   std::string graph_title = clip.empty() ? "" : "video " + clip;
   VideoQualityTest::Params params{
-      {
-        flags::Width(),
-        flags::Height(),
-        flags::Fps(),
-        flags::MinBitrateKbps() * 1000,
-        flags::TargetBitrateKbps() * 1000,
-        flags::MaxBitrateKbps() * 1000,
-        flags::Codec(),
-        flags::NumTemporalLayers(),
-        0,  // No min transmit bitrate.
-        call_bitrate_config,
-        flags::TLDiscardThreshold()
-      },
+      {flags::Width(), flags::Height(), flags::Fps(),
+       flags::MinBitrateKbps() * 1000, flags::TargetBitrateKbps() * 1000,
+       flags::MaxBitrateKbps() * 1000, flags::Codec(),
+       flags::NumTemporalLayers(),
+       0,  // No min transmit bitrate.
+       call_bitrate_config, flags::TLDiscardThreshold(),
+       flags::FLAGS_send_side_bwe},
       {clip},
       {},  // Screenshare specific.
       {graph_title, 0.0, 0.0, flags::DurationSecs(), flags::OutputFilename()},