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diff --git a/components/policy/core/common/external_data_fetcher.h b/components/policy/core/common/external_data_fetcher.h
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+++ b/components/policy/core/common/external_data_fetcher.h
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+// 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_EXTERNAL_DATA_FETCHER_H_
+#define COMPONENTS_POLICY_CORE_COMMON_EXTERNAL_DATA_FETCHER_H_
+
+#include <memory>
+#include <string>
+
+#include "base/callback_forward.h"
+#include "base/memory/weak_ptr.h"
+#include "components/policy/policy_export.h"
+
+namespace policy {
+
+class ExternalDataManager;
+
+// A helper that encapsulates the parameters required to retrieve the external
+// data for a policy.
+class POLICY_EXPORT ExternalDataFetcher {
+ public:
+  typedef base::Callback<void(std::unique_ptr<std::string>)> FetchCallback;
+
+  // This instance's Fetch() method will instruct the |manager| to retrieve the
+  // external data referenced by the given |policy|.
+  ExternalDataFetcher(base::WeakPtr<ExternalDataManager> manager,
+                      const std::string& policy);
+  ExternalDataFetcher(const ExternalDataFetcher& other);
+
+  ~ExternalDataFetcher();
+
+  static bool Equals(const ExternalDataFetcher* first,
+                     const ExternalDataFetcher* second);
+
+  // Retrieves the external data referenced by |policy_| and invokes |callback|
+  // with the result. If |policy_| does not reference any external data, the
+  // |callback| is invoked with a NULL pointer. Otherwise, the |callback| is
+  // invoked with the referenced data once it has been successfully retrieved.
+  // If retrieval is temporarily impossible (e.g. no network connectivity), the
+  // |callback| will be invoked when the temporary hindrance is resolved. If
+  // retrieval is permanently impossible (e.g. |policy_| references data that
+  // does not exist on the server), the |callback| will never be invoked.
+  void Fetch(const FetchCallback& callback) const;
+
+ private:
+  base::WeakPtr<ExternalDataManager> manager_;
+  const std::string policy_;
+};
+
+}  // namespace policy
+
+#endif  // COMPONENTS_POLICY_CORE_COMMON_EXTERNAL_DATA_FETCHER_H_