Makes RoundRobinPacketQueue use same field trials as PacingController.

A bug currently causes the packet queue to not get any trials enabled
unless an injected key value map is used.

Bug: None
Change-Id: I5c21aa296e8a202a63e81a57c5d13297ad7333bd
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/160012
Reviewed-by: Christoffer Rodbro <crodbro@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Erik Språng <sprang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29845}
diff --git a/modules/pacing/pacing_controller.cc b/modules/pacing/pacing_controller.cc
index 5b7dda3..16d1f36 100644
--- a/modules/pacing/pacing_controller.cc
+++ b/modules/pacing/pacing_controller.cc
@@ -113,7 +113,7 @@
       pacing_bitrate_(DataRate::Zero()),
       last_process_time_(clock->CurrentTime()),
       last_send_time_(last_process_time_),
-      packet_queue_(last_process_time_, field_trials),
+      packet_queue_(last_process_time_, field_trials_),
       packet_counter_(0),
       congestion_window_size_(DataSize::PlusInfinity()),
       outstanding_data_(DataSize::Zero()),