Sets sending status for active RtpRtcp modules.

When a simulcast stream is enabled or disabled, we want this state
change to be reflected properly in the RtpRtcp modules. Each video send
stream can contain multiple rtp_rtcp_modules pertaining to different
simulcast streams. These modules are currently all turned on/off when
the send stream is started and stopped. This change allows for
individual modules to be turned on/off. This means if a module stops
sending it will send a bye message, so the receiving side will not
expect more frames to be sent when the stream is inactive and the
encoder is no longer encoding/sending images.

Bug: webrtc:8653
Change-Id: Ib6d00240f627b4ff1714646e847026f24c7c3aa4
Reviewed-on: https://webrtc-review.googlesource.com/42841
Commit-Queue: Seth Hampson <shampson@webrtc.org>
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Reviewed-by: Stefan Holmer <stefan@webrtc.org>
Reviewed-by: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#21880}
diff --git a/test/encoder_settings.cc b/test/encoder_settings.cc
index 205af7b..685ec63 100644
--- a/test/encoder_settings.cc
+++ b/test/encoder_settings.cc
@@ -50,7 +50,13 @@
         std::min(bitrate_left_bps,
                  DefaultVideoStreamFactory::kMaxBitratePerStream[i]);
     stream_settings[i].max_qp = 56;
-    stream_settings[i].active = true;
+    if (i < encoder_config.simulcast_layers.size()) {
+      // Higher level controls are setting the active configuration for the
+      // VideoStream.
+      stream_settings[i].active = encoder_config.simulcast_layers[i].active;
+    } else {
+      stream_settings[i].active = true;
+    }
     bitrate_left_bps -= stream_settings[i].target_bitrate_bps;
   }
 
@@ -78,6 +84,7 @@
   configuration->video_stream_factory =
       new rtc::RefCountedObject<DefaultVideoStreamFactory>();
   configuration->max_bitrate_bps = 0;
+  configuration->simulcast_layers = std::vector<VideoStream>(num_streams);
   for (size_t i = 0; i < num_streams; ++i) {
     configuration->max_bitrate_bps +=
         DefaultVideoStreamFactory::kMaxBitratePerStream[i];