Fix race issue in ArcAuthService.

chrome/browser/chromeos/arc/arc_auth_code_fetcher.h

-// Copyright 2016 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 CHROME_BROWSER_CHROMEOS_ARC_ARC_AUTH_CODE_FETCHER_H_
-#define CHROME_BROWSER_CHROMEOS_ARC_ARC_AUTH_CODE_FETCHER_H_
-
-#include <memory>
-#include <string>
-
-#include "base/callback.h"
-#include "base/macros.h"
-#include "base/memory/weak_ptr.h"
-#include "chrome/browser/chromeos/arc/arc_auth_context.h"
-#include "google_apis/gaia/oauth2_token_service.h"
-#include "net/url_request/url_fetcher_delegate.h"
-
-class Profile;
-
-namespace net {
-class URLFetcher;
-class URLRequestContextGetter;
-}
-
-namespace arc {
-
-// The instance is not reusable, so for each Fetch(), the instance must be
-// re-created. Deleting the instance cancels inflight operation.
-class ArcAuthCodeFetcher : public OAuth2TokenService::Consumer,
-                           public net::URLFetcherDelegate {
- public:
-  ArcAuthCodeFetcher(Profile* profile, ArcAuthContext* context);
-  ~ArcAuthCodeFetcher() override;
-
-  // Starts to fetch the token. On success fetched |auth_token| is passed.
-  // On error, auth_token is empty.
-  using FetchCallback = base::Callback<void(const std::string& auth_token)>;
-  void Fetch(const FetchCallback& callback);
-
-  // 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;
-
-  // net::URLFetcherDelegate:
-  void OnURLFetchComplete(const net::URLFetcher* source) override;
-
- private:
-  void ResetFetchers();
-  void OnPrepared(net::URLRequestContextGetter* request_context_getter);
-
-  // Unowned pointers.
-  Profile* const profile_;
-  ArcAuthContext* const context_;
-  net::URLRequestContextGetter* request_context_getter_ = nullptr;
-
-  FetchCallback callback_;
-
-  std::unique_ptr<OAuth2TokenService::Request> login_token_request_;
-  std::unique_ptr<net::URLFetcher> auth_code_fetcher_;
-
-  base::WeakPtrFactory<ArcAuthCodeFetcher> weak_ptr_factory_;
-
-  DISALLOW_COPY_AND_ASSIGN(ArcAuthCodeFetcher);
-};
-
-}  // namespace arc
-
-#endif  // CHROME_BROWSER_CHROMEOS_ARC_ARC_AUTH_CODE_FETCHER_H_