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:
+  // Callback that is called when all the address normalization requests have
+  // completed.
+  using CompletionCallback =
+      base::OnceCallback<void(const AddressNormalizationManager&)>;

[Mathieu, 2017/05/17 16:45:14]

can this be a base::OnceClosure()? If so, perhaps you don't need the typedef at
all

[macourteau, 2017/05/17 18:38:40]

Done.

+
+  // 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,

[Mathieu, 2017/05/17 16:45:14]

can we remove the std::unique_ptr?

[macourteau, 2017/05/17 18:38:40]

The alternative would be for the caller to own the AddressNormalizer, but it
would still have to be a pointer, since AddressNormalizer is a pure virtual
class, and actual objects are either AddressNormalizerImpl or
TestAddressNormalizer instances.

+      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.

[Mathieu, 2017/05/17 16:45:14]

you should mention how to get the normalized addresses from the manager.

[macourteau, 2017/05/17 18:38:40]

This is mentioned in the documentation for StartNormalizingAddress below ("On
completion, the address in |profile| will be updated with the normalized
address.").

+  void FinalizeWithCompletionCallback(CompletionCallback 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);
+
+ private:
+  class NormalizerDelegate;

[Mathieu, 2017/05/17 16:45:14]

why not declare the whole class here?

[macourteau, 2017/05/17 18:38:40]

Figured it was an implementation detail, and users of this class don't need to
know (also: shorter header file). I can move it here if you'd prefer, I don't
have a strong opinion.

[Mathieu, 2017/05/17 19:47:33]

Yeah, I don't see this pattern a lot so I would prefer having it declared here,
thanks

[macourteau, 2017/05/17 19:52:04]

Done.

+  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.
+  std::string default_country_code_;

[Mathieu, 2017/05/17 16:45:14]

nit: const?

[macourteau, 2017/05/17 18:38:40]

Done.

+
+  // The callback to execute when all addresses have been normalized.
+  CompletionCallback 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_