Replace deprecated base::NonThreadSafe in components/signin in favor of SequenceChecker.

components/signin/core/browser/refresh_token_annotation_request.h

Index: components/signin/core/browser/refresh_token_annotation_request.h
diff --git a/components/signin/core/browser/refresh_token_annotation_request.h b/components/signin/core/browser/refresh_token_annotation_request.h
index 483830bfea458e6948e10e337b5d669e5395e1fa..4965ef85edb1e246c8cdc4964492b8a1683f130e 100644
--- a/components/signin/core/browser/refresh_token_annotation_request.h
+++ b/components/signin/core/browser/refresh_token_annotation_request.h
@@ -10,7 +10,7 @@
 #include "base/callback.h"
 #include "base/gtest_prod_util.h"
 #include "base/macros.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "google_apis/gaia/oauth2_api_call_flow.h"
 #include "google_apis/gaia/oauth2_token_service.h"
 
@@ -22,8 +22,7 @@ class SigninClient;
 // important to keep server QPS low therefore this request is sent on average
 // once per 10 days per profile.
 // This code shold be removed once majority of refresh tokens are updated.
-class RefreshTokenAnnotationRequest : public base::NonThreadSafe,
-                                      public OAuth2TokenService::Consumer,
+class RefreshTokenAnnotationRequest : public OAuth2TokenService::Consumer,
                                       public OAuth2ApiCallFlow {
  public:
   ~RefreshTokenAnnotationRequest() override;
@@ -84,6 +83,8 @@ class RefreshTokenAnnotationRequest : public base::NonThreadSafe,
 
   std::unique_ptr<OAuth2TokenService::Request> access_token_request_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(RefreshTokenAnnotationRequest);
 };