Read the number of TLs for VP9 too + cleanup

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 9897783eb9ddf8ff59d644722b624943b403978c..1713cd6f8269318aa05e6a6a96f930e367d84c86 100644
--- a/webrtc/video/screenshare_loopback.cc
+++ b/webrtc/video/screenshare_loopback.cc
@@ -83,6 +83,11 @@ size_t TLDiscardThreshold() {
   return static_cast<size_t>(FLAGS_tl_discard_threshold);
 }
 
+DEFINE_bool(disable_frame_dropper,
+            false,
+            "Disable generic bitrate frame dropper in the wrapper. "
+            "Does not affect drop on capture or PacedSender.");
+
 DEFINE_int32(min_transmit_bitrate, 400, "Min transmit bitrate incl. padding.");
 int MinTransmitBitrateKbps() {
   return FLAGS_min_transmit_bitrate;
@@ -169,7 +174,7 @@ void Loopback() {
        flags::MaxBitrateKbps() * 1000, flags::Codec(),
        flags::NumTemporalLayers(), flags::MinTransmitBitrateKbps() * 1000,
        call_bitrate_config, flags::TLDiscardThreshold(),
-       flags::FLAGS_send_side_bwe},
+       flags::FLAGS_send_side_bwe, flags::FLAGS_disable_frame_dropper},
       {},  // Video specific.
       {true, flags::SlideChangeInterval(), flags::ScrollDuration()},
       {"screenshare", 0.0, 0.0, flags::DurationSecs(), flags::OutputFilename()},