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

chrome/browser/process_singleton_startup_lock.h

 // Copyright (c) 2013 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_BROWSER_PROCESS_SINGLETON_STARTUP_LOCK_H_
 #define CHROME_BROWSER_PROCESS_SINGLETON_STARTUP_LOCK_H_
 
 #include <set>
 #include <utility>
 #include <vector>
 
 #include "base/command_line.h"
 #include "base/files/file_path.h"
 #include "base/macros.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "chrome/browser/process_singleton.h"
 
 // Provides a ProcessSingleton::NotificationCallback that can queue up
 // command-line invocations during startup and execute them when startup
 // completes.
 //
 // The object starts in a locked state. |Unlock()| must be called
 // when the process is prepared to handle command-line invocations.
 //
 // Once unlocked, notifications are forwarded to a wrapped NotificationCallback.
-class ProcessSingletonStartupLock : public base::NonThreadSafe {
+class ProcessSingletonStartupLock {
  public:
   explicit ProcessSingletonStartupLock(
       const ProcessSingleton::NotificationCallback& original_callback);
   ~ProcessSingletonStartupLock();
 
   // Returns the ProcessSingleton::NotificationCallback.
   // The callback is only valid during the lifetime of the
   // ProcessSingletonStartupLock instance.
   ProcessSingleton::NotificationCallback AsNotificationCallback();
 
   // Executes previously queued command-line invocations and allows future
   // invocations to be executed immediately.
   void Unlock();
 
   bool locked() { return locked_; }
 
  private:
   typedef std::pair<base::CommandLine::StringVector, base::FilePath>
       DelayedStartupMessage;
 
   bool NotificationCallbackImpl(const base::CommandLine& command_line,
                                 const base::FilePath& current_directory);
 
   bool locked_;
   std::vector<DelayedStartupMessage> saved_startup_messages_;
   ProcessSingleton::NotificationCallback original_callback_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(ProcessSingletonStartupLock);
 };
 
 #endif  // CHROME_BROWSER_PROCESS_SINGLETON_STARTUP_LOCK_H_