Replace deprecated base::NonThreadSafe in chrome/browser/metrics/perf in favor of SequenceChecker.

chrome/browser/metrics/perf/perf_provider_chromeos.h

Index: chrome/browser/metrics/perf/perf_provider_chromeos.h
diff --git a/chrome/browser/metrics/perf/perf_provider_chromeos.h b/chrome/browser/metrics/perf/perf_provider_chromeos.h
index 15a5b8eb2fa2c7216624574bb5198634ff5d8ced..945a09d71a573080f7531172600643435fac879c 100644
--- a/chrome/browser/metrics/perf/perf_provider_chromeos.h
+++ b/chrome/browser/metrics/perf/perf_provider_chromeos.h
@@ -11,7 +11,7 @@
 #include <vector>
 
 #include "base/macros.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "base/time/time.h"
 #include "base/timer/timer.h"
 #include "chrome/browser/metrics/perf/cpu_identity.h"
@@ -29,8 +29,7 @@ class WindowedIncognitoObserver;
 // Provides access to ChromeOS perf data. perf aka "perf events" is a
 // performance profiling infrastructure built into the linux kernel. For more
 // information, see: https://perf.wiki.kernel.org/index.php/Main_Page.
-class PerfProvider : public base::NonThreadSafe,
-                     public chromeos::PowerManagerClient::Observer {
+class PerfProvider : public chromeos::PowerManagerClient::Observer {
  public:
   PerfProvider();
   ~PerfProvider() override;
@@ -255,6 +254,8 @@ class PerfProvider : public base::NonThreadSafe,
   SessionRestore::CallbackSubscription
       on_session_restored_callback_subscription_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   // To pass around the "this" pointer across threads safely.
   base::WeakPtrFactory<PerfProvider> weak_factory_;