Adds the AddressNormalizationManager and tests.

components/payments/core/address_normalization_manager.h

+// Copyright 2017 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_PAYMENTS_CORE_ADDRESS_NORMALIZATION_MANAGER_H_
+#define COMPONENTS_PAYMENTS_CORE_ADDRESS_NORMALIZATION_MANAGER_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/threading/thread_checker.h"
+
+namespace autofill {
+class AutofillProfile;
+}  // namespace autofill
+
+namespace payments {
+
+class AddressNormalizer;
+
+// Class to handle multiple concurrent address normalization requests. This
+// class is not thread-safe.
+class AddressNormalizationManager {
+ public:
+  // Initializes an AddressNormalizationManager. |default_country_code| will be
+  // used if the country code in an AutofillProfile to normalize is not valid.
+  // The AddressNormalizationManager takes ownership of |address_normalizer|.
+  AddressNormalizationManager(
+      std::unique_ptr<AddressNormalizer> address_normalizer,
+      const std::string& default_country_code);
+
+  ~AddressNormalizationManager();
+
+  // Stops accepting normalization requests. If all the address normalization
+  // requests have already completed, |completion_callback| will be called
+  // before this method returns. Otherwise, it will be called as soon as the
+  // last pending request completes.
+  void FinalizeWithCompletionCallback(base::OnceClosure completion_callback);
+
+  // Normalizes the address in |profile|. This may or may not happen
+  // asynchronously. On completion, the address in |profile| will be updated
+  // with the normalized address.
+  void StartNormalizingAddress(autofill::AutofillProfile* profile);

[sebsg, 2017/05/17 19:30:23]

My only concern is this modification of the profile, and is more related to the
use of this class than the class itself.

If you were planning to make a copy of the profile and pass the pointer to the
copy in this function then everything is perfect :)

Otherwise here is my concern:

The reason why the original code sends a copy is that I don't want to have the
original profile be normalized. For example, The phone number will be normalized
in E.164 format which is not the format we want to save or show to the user. 

[macourteau, 2017/05/17 19:41:10]

Ok, good to know. Will make sure the code using this makes a copy (not relevant
to this CL though).

+
+ private:
+  class NormalizerDelegate;
+  friend class NormalizerDelegate;
+
+  // Runs the completion callback if all the delegates have completed.
+  void MaybeRunCompletionCallback();
+
+  // Whether the AddressNormalizationManager is still accepting requests or not.
+  bool accepting_requests_ = true;
+
+  // The default country code to use if a profile does not have a valid country.
+  const std::string default_country_code_;
+
+  // The callback to execute when all addresses have been normalized.
+  base::OnceClosure completion_callback_;
+
+  // Storage for all the delegates that handle the normalization requests.
+  std::vector<std::unique_ptr<NormalizerDelegate>> delegates_;
+
+  // The AddressNormalizer to use. Owned by this class.
+  std::unique_ptr<AddressNormalizer> address_normalizer_;
+
+  THREAD_CHECKER(thread_checker_);
+  DISALLOW_COPY_AND_ASSIGN(AddressNormalizationManager);
+};
+
+}  // namespace payments
+
+#endif  // COMPONENTS_PAYMENTS_CORE_ADDRESS_NORMALIZATION_MANAGER_H_