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

extensions/browser/extension_throttle_manager.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 EXTENSIONS_BROWSER_EXTENSION_THROTTLE_MANAGER_H_
 #define EXTENSIONS_BROWSER_EXTENSION_THROTTLE_MANAGER_H_
 
 #include <map>
 #include <memory>
 #include <string>
 
 #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/platform_thread.h"
 #include "extensions/browser/extension_throttle_entry.h"
 #include "net/base/backoff_entry.h"
 #include "net/base/net_export.h"
 #include "net/base/network_change_notifier.h"
 #include "url/gurl.h"
 
 namespace content {
 class ResourceThrottle;
 }
 
 namespace net {
 class NetLog;
 class NetLogWithSource;
 }
 
 namespace extensions {
 
 // Class that registers URL request throttler entries for URLs being accessed
 // in order to supervise traffic. URL requests for HTTP contents should
 // register their URLs in this manager on each request.
 //
 // ExtensionThrottleManager maintains a map of URL IDs to URL request
 // throttler entries. It creates URL request throttler entries when new URLs
 // are registered, and does garbage collection from time to time in order to
 // clean out outdated entries. URL ID consists of lowercased scheme, host, port
 // and path. All URLs converted to the same ID will share the same entry.
 class ExtensionThrottleManager
-    : NON_EXPORTED_BASE(public base::NonThreadSafe),
-      public net::NetworkChangeNotifier::IPAddressObserver,
+    : public net::NetworkChangeNotifier::IPAddressObserver,
       public net::NetworkChangeNotifier::ConnectionTypeObserver {
  public:
   ExtensionThrottleManager();
   ~ExtensionThrottleManager() override;
 
   // Creates a content::ResourceThrottle for |request| to prevent extensions
   // from requesting a URL too often, if such a throttle is needed.
   std::unique_ptr<content::ResourceThrottle> MaybeCreateThrottle(
       const net::URLRequest* request);
 
@@ skipping 116 matching lines @@
   net::NetLogWithSource net_log_;
 
   // Valid once we've registered for network notifications.
   base::PlatformThreadId registered_from_thread_;
 
   bool ignore_user_gesture_load_flag_for_tests_;
 
   // This is NULL when it is not set for tests.
   std::unique_ptr<net::BackoffEntry::Policy> backoff_policy_for_tests_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionThrottleManager);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_BROWSER_EXTENSION_THROTTLE_MANAGER_H_