Replace deprecated base::NonThreadSafe in chrome/service in favor of SequenceChecker.

chrome/service/cloud_print/cloud_print_proxy.h

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_SERVICE_CLOUD_PRINT_CLOUD_PRINT_PROXY_H_
 #define CHROME_SERVICE_CLOUD_PRINT_CLOUD_PRINT_PROXY_H_
 
 #include <list>
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/macros.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "chrome/service/cloud_print/cloud_print_proxy_backend.h"
 #include "chrome/service/cloud_print/cloud_print_wipeout.h"
 
 class ServiceProcessPrefs;
 
 namespace cloud_print {
 
 struct CloudPrintProxyInfo;
 
 // CloudPrintProxy is the layer between the service process UI thread
 // and the cloud print proxy backend.
 class CloudPrintProxy : public CloudPrintProxyFrontend,
-                        public CloudPrintWipeout::Client,
-                        public base::NonThreadSafe {
+                        public CloudPrintWipeout::Client {
  public:
   class Client {
    public:
     virtual ~Client() {}
     virtual void OnCloudPrintProxyEnabled(bool persist_state) {}
     virtual void OnCloudPrintProxyDisabled(bool persist_state) {}
   };
   CloudPrintProxy();
   ~CloudPrintProxy() override;
 
@@ skipping 53 matching lines @@
   Client* client_;
   // The email address of the account used to authenticate to the Cloud Print
   // service.
   std::string user_email_;
   // This is set to true when the Cloud Print proxy is enabled and after
   // successful authentication with the Cloud Print service.
   bool enabled_;
   // This is a cleanup class for unregistering printers on proxy disable.
   std::unique_ptr<CloudPrintWipeout> wipeout_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(CloudPrintProxy);
 };
 
 }  // namespace cloud_print
 
 #endif  // CHROME_SERVICE_CLOUD_PRINT_CLOUD_PRINT_PROXY_H_