Deprecate NonThreadSafe in chromeos/process_proxy in favor of SequenceChecker.

chromeos/process_proxy/process_proxy_registry.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 CHROMEOS_PROCESS_PROXY_PROCESS_PROXY_REGISTRY_H_
 #define CHROMEOS_PROCESS_PROXY_PROCESS_PROXY_REGISTRY_H_
 
 #include <map>
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/lazy_instance.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "base/threading/thread.h"
 #include "chromeos/chromeos_export.h"
 #include "chromeos/process_proxy/process_proxy.h"
 
 namespace chromeos {
 
 // Keeps track of all created ProcessProxies. It is created lazily and should
 // live on a single thread (where all methods must be called).
-class CHROMEOS_EXPORT ProcessProxyRegistry : public base::NonThreadSafe {
+class CHROMEOS_EXPORT ProcessProxyRegistry {
  public:
   using OutputCallback = base::Callback<void(int terminal_id,
                                              const std::string& output_type,
                                              const std::string& output_data)>;
 
   // Info we need about a ProcessProxy instance.
   struct ProcessProxyInfo {
     scoped_refptr<ProcessProxy> proxy;
     OutputCallback callback;
 
@@ skipping 30 matching lines @@
   // Gets called when output gets detected.
   void OnProcessOutput(int id, ProcessOutputType type, const std::string& data);
 
   bool EnsureWatcherThreadStarted();
 
   // Map of all existing ProcessProxies.
   std::map<int, ProcessProxyInfo> proxy_map_;
 
   std::unique_ptr<base::Thread> watcher_thread_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(ProcessProxyRegistry);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_PROCESS_PROXY_PROCESS_PROXY_REGISTRY_H_