Wire up send-side bandwidth estimation.

webrtc/video/screenshare_loopback.cc

Index: webrtc/video/screenshare_loopback.cc
diff --git a/webrtc/video/screenshare_loopback.cc b/webrtc/video/screenshare_loopback.cc
index a221e9c52f14e44797b853ac2fa5b655b9a8f25a..ec9ed5bd86bb5479c48fd6d78cf3479e1b6f4cdb 100644
--- a/webrtc/video/screenshare_loopback.cc
+++ b/webrtc/video/screenshare_loopback.cc
@@ -142,6 +142,8 @@ int StdPropagationDelayMs() {
 
 DEFINE_bool(logs, false, "print logs to stderr");
 
+DEFINE_bool(send_side_bwe, false, "Use send-side bandwidth estimation");
+
 DEFINE_string(
     force_fieldtrials,
     "",
@@ -256,7 +258,8 @@ void Loopback() {
                                 flags::QueueSize(),
                                 flags::AvgPropagationDelayMs(),
                                 flags::StdPropagationDelayMs(),
-                                flags::FLAGS_logs};
+                                flags::FLAGS_logs,
+                                flags::FLAGS_send_side_bwe};
   ScreenshareLoopback loopback(config);
   loopback.Run();
 }