Refactor CryptAuth component to be more testable.

components/proximity_auth/cryptauth/cryptauth_account_token_fetcher.h

-// Copyright 2014 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_PROXIMITY_AUTH_CRYPT_AUTH_ACCOUNT_TOKEN_FETCHER_IMPL_H
-#define COMPONENTS_PROXIMITY_AUTH_CRYPT_AUTH_ACCOUNT_TOKEN_FETCHER_IMPL_H
-
-#include "base/callback.h"
-#include "components/proximity_auth/cryptauth/cryptauth_access_token_fetcher.h"
-#include "google_apis/gaia/oauth2_token_service.h"
-
-namespace proximity_auth {
-
-// Implementation of CryptAuthAccessTokenFetcher fetching an access token for a
-// given account using the provided OAuth2TokenService.
-class CryptAuthAccountTokenFetcher : public CryptAuthAccessTokenFetcher,
-                                     public OAuth2TokenService::Consumer {
- public:
-  // |token_service| is not owned, and must outlive this object.
-  CryptAuthAccountTokenFetcher(OAuth2TokenService* token_service,
-                               const std::string& account_id);
-  ~CryptAuthAccountTokenFetcher() override;
-
-  // CryptAuthAccessTokenFetcher:
-  void FetchAccessToken(const AccessTokenCallback& callback) override;
-
- private:
-  // OAuth2TokenService::Consumer:
-  void OnGetTokenSuccess(const OAuth2TokenService::Request* request,
-                         const std::string& access_token,
-                         const base::Time& expiration_time) override;
-  void OnGetTokenFailure(const OAuth2TokenService::Request* request,
-                         const GoogleServiceAuthError& error) override;
-
-  // System service that caches and fetches tokens for a given account.
-  // Not owned.
-  OAuth2TokenService* token_service_;
-
-  // The account id for whom to mint the token.
-  std::string account_id_;
-
-  // True if FetchAccessToken() has been called.
-  bool fetch_started_;
-
-  // Stores the request from |token_service_| to mint the token.
-  scoped_ptr<OAuth2TokenService::Request> token_request_;
-
-  // Callback to invoke when the token fetch succeeds or fails.
-  AccessTokenCallback callback_;
-
-  DISALLOW_COPY_AND_ASSIGN(CryptAuthAccountTokenFetcher);
-};
-
-}  // namespace proximity_auth
-
-#endif  // COMPONENTS_PROXIMITY_AUTH_CRYPT_AUTH_ACCESS_TOKEN_FETCHER_IMPL_H