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

components/policy/core/common/async_policy_provider.h

 // Copyright 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 COMPONENTS_POLICY_CORE_COMMON_ASYNC_POLICY_PROVIDER_H_
 #define COMPONENTS_POLICY_CORE_COMMON_ASYNC_POLICY_PROVIDER_H_
 
 #include <memory>
 
 #include "base/cancelable_callback.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
-#include "base/threading/non_thread_safe.h"
+#include "base/sequence_checker.h"
 #include "components/policy/core/common/configuration_policy_provider.h"
 #include "components/policy/policy_export.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace policy {
 
 class AsyncPolicyLoader;
 class PolicyBundle;
 class SchemaRegistry;
 
 // A policy provider that loads its policies asynchronously on a background
 // thread. Platform-specific providers are created by passing an implementation
 // of AsyncPolicyLoader to a new AsyncPolicyProvider.
-class POLICY_EXPORT AsyncPolicyProvider : public ConfigurationPolicyProvider,
-                                          public base::NonThreadSafe {
+class POLICY_EXPORT AsyncPolicyProvider : public ConfigurationPolicyProvider {
  public:
   // The AsyncPolicyProvider does a synchronous load in its constructor, and
   // therefore it needs the |registry| at construction time. The same |registry|
   // should be passed later to Init().
   AsyncPolicyProvider(SchemaRegistry* registry,
                       std::unique_ptr<AsyncPolicyLoader> loader);
   ~AsyncPolicyProvider() override;
 
   // ConfigurationPolicyProvider implementation.
   void Init(SchemaRegistry* registry) override;
@@ skipping 17 matching lines @@
       std::unique_ptr<PolicyBundle> bundle);
 
   // The |loader_| that does the platform-specific policy loading. It lives
   // on the background thread but is owned by |this|.
   std::unique_ptr<AsyncPolicyLoader> loader_;
 
   // Callback used to synchronize RefreshPolicies() calls with the background
   // thread. See the implementation for the details.
   base::CancelableClosure refresh_callback_;
 
+  SEQUENCE_CHECKER(sequence_checker_);
+
   // Used to get a WeakPtr to |this| for the update callback given to the
   // loader.
   base::WeakPtrFactory<AsyncPolicyProvider> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(AsyncPolicyProvider);
 };
 
 }  // namespace policy
 
 #endif  // COMPONENTS_POLICY_CORE_COMMON_ASYNC_POLICY_PROVIDER_H_