Use SequenceChecker from public API

Bug: webrtc:12419
Change-Id: I00cca16a0ec70246156ba00b97aa7ae5ccbf5364
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/205323
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33220}
diff --git a/modules/pacing/task_queue_paced_sender.h b/modules/pacing/task_queue_paced_sender.h
index ba4f466..dc4c124 100644
--- a/modules/pacing/task_queue_paced_sender.h
+++ b/modules/pacing/task_queue_paced_sender.h
@@ -20,6 +20,7 @@
 #include <vector>
 
 #include "absl/types/optional.h"
+#include "api/sequence_checker.h"
 #include "api/task_queue/task_queue_factory.h"
 #include "api/units/data_size.h"
 #include "api/units/time_delta.h"
@@ -30,7 +31,6 @@
 #include "modules/pacing/rtp_packet_pacer.h"
 #include "modules/rtp_rtcp/source/rtp_packet_to_send.h"
 #include "rtc_base/synchronization/mutex.h"
-#include "rtc_base/synchronization/sequence_checker.h"
 #include "rtc_base/task_queue.h"
 #include "rtc_base/thread_annotations.h"