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/rtc_tools/network_tester/test_controller.h b/rtc_tools/network_tester/test_controller.h
index 20f580e..50055fc 100644
--- a/rtc_tools/network_tester/test_controller.h
+++ b/rtc_tools/network_tester/test_controller.h
@@ -19,13 +19,13 @@
 #include <string>
 
 #include "absl/types/optional.h"
+#include "api/sequence_checker.h"
 #include "p2p/base/basic_packet_socket_factory.h"
 #include "rtc_base/async_packet_socket.h"
 #include "rtc_base/constructor_magic.h"
 #include "rtc_base/ignore_wundef.h"
 #include "rtc_base/socket_address.h"
 #include "rtc_base/synchronization/mutex.h"
-#include "rtc_base/synchronization/sequence_checker.h"
 #include "rtc_base/third_party/sigslot/sigslot.h"
 #include "rtc_base/thread_annotations.h"
 #include "rtc_tools/network_tester/packet_logger.h"