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/pc/remote_audio_source.cc b/pc/remote_audio_source.cc
index 50e9c55..3f53bb8 100644
--- a/pc/remote_audio_source.cc
+++ b/pc/remote_audio_source.cc
@@ -16,11 +16,11 @@
 
 #include "absl/algorithm/container.h"
 #include "api/scoped_refptr.h"
+#include "api/sequence_checker.h"
 #include "rtc_base/checks.h"
 #include "rtc_base/location.h"
 #include "rtc_base/logging.h"
 #include "rtc_base/strings/string_format.h"
-#include "rtc_base/synchronization/sequence_checker.h"
 #include "rtc_base/thread.h"
 
 namespace webrtc {