Allow packets to be reordered in the fake network pipe.

BUG=

Review URL: https://codereview.webrtc.org/1606183002

Cr-Original-Commit-Position: refs/heads/master@{#11384}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: a2c55235cae5f16715911bff6109fe915a8085bf
diff --git a/video/screenshare_loopback.cc b/video/screenshare_loopback.cc
index 6479aa4..91002ef 100644
--- a/video/screenshare_loopback.cc
+++ b/video/screenshare_loopback.cc
@@ -174,6 +174,8 @@
 
 DEFINE_bool(send_side_bwe, true, "Use send-side bandwidth estimation");
 
+DEFINE_bool(allow_reordering, false, "Allow packet reordering to occur");
+
 DEFINE_string(
     force_fieldtrials,
     "",
@@ -212,6 +214,7 @@
   pipe_config.queue_length_packets = flags::QueueSize();
   pipe_config.queue_delay_ms = flags::AvgPropagationDelayMs();
   pipe_config.delay_standard_deviation_ms = flags::StdPropagationDelayMs();
+  pipe_config.allow_reordering = flags::FLAGS_allow_reordering;
 
   Call::Config::BitrateConfig call_bitrate_config;
   call_bitrate_config.min_bitrate_bps = flags::MinBitrateKbps() * 1000;