Replace rtc::ThreadChecker with webrtc::SequenceChecker

Bug: webrtc:12419
Change-Id: I825c014cc1c4b1dcba5ef300409d44859e971144
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/205002
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Tommi <tommi@webrtc.org>
Commit-Queue: Artem Titov <titovartem@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#33136}
diff --git a/modules/video_coding/generic_decoder.h b/modules/video_coding/generic_decoder.h
index 9524bab..8f41690 100644
--- a/modules/video_coding/generic_decoder.h
+++ b/modules/video_coding/generic_decoder.h
@@ -21,7 +21,7 @@
 #include "modules/video_coding/timing.h"
 #include "rtc_base/experiments/field_trial_parser.h"
 #include "rtc_base/synchronization/mutex.h"
-#include "rtc_base/thread_checker.h"
+#include "rtc_base/synchronization/sequence_checker.h"
 
 namespace webrtc {
 
@@ -61,7 +61,7 @@
   int32_t Pop(uint32_t timestamp);
 
  private:
-  rtc::ThreadChecker construction_thread_;
+  SequenceChecker construction_thread_;
   // Protect |_timestampMap|.
   Clock* const _clock;
   // This callback must be set before the decoder thread starts running