Remove deprecated thread checker

Bug: webrtc:12419
Change-Id: Ie617a15c29a6b250a4c1bf36da113bb6d5b41d1f
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/206642
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33216}
diff --git a/api/BUILD.gn b/api/BUILD.gn
index fba4411..0a6c670 100644
--- a/api/BUILD.gn
+++ b/api/BUILD.gn
@@ -175,6 +175,7 @@
     ":rtp_parameters",
     ":rtp_transceiver_direction",
     ":scoped_refptr",
+    ":sequence_checker",
     "../rtc_base:network_constants",
     "adaptation:resource_adaptation_api",
     "audio:audio_mixer_api",
diff --git a/api/stats_types.h b/api/stats_types.h
index c1922a8..f910b4a 100644
--- a/api/stats_types.h
+++ b/api/stats_types.h
@@ -21,11 +21,11 @@
 #include <vector>
 
 #include "api/scoped_refptr.h"
+#include "api/sequence_checker.h"
 #include "rtc_base/constructor_magic.h"
 #include "rtc_base/ref_count.h"
 #include "rtc_base/string_encode.h"
 #include "rtc_base/system/rtc_export.h"
-#include "rtc_base/thread_checker.h"
 
 namespace webrtc {
 
@@ -344,7 +344,7 @@
     const StatsValueName name;
 
    private:
-    rtc::ThreadChecker thread_checker_;
+    webrtc::SequenceChecker thread_checker_;
     mutable int ref_count_ RTC_GUARDED_BY(thread_checker_) = 0;
 
     const Type type_;
@@ -447,7 +447,7 @@
 
  private:
   Container list_;
-  rtc::ThreadChecker thread_checker_;
+  webrtc::SequenceChecker thread_checker_;
 };
 
 }  // namespace webrtc