Create AccountServiceFlagFetcher which downloads an account's Gaia service flags.

chrome/browser/signin/account_service_flag_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 CHROME_BROWSER_SIGNIN_ACCOUNT_SERVICE_FLAG_FETCHER_H_
+#define CHROME_BROWSER_SIGNIN_ACCOUNT_SERVICE_FLAG_FETCHER_H_
+
+#include <string>
+#include <vector>
+
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "google_apis/gaia/gaia_auth_consumer.h"
+#include "google_apis/gaia/gaia_auth_fetcher.h"
+#include "google_apis/gaia/oauth2_token_service.h"
+
+class Profile;
+
+// Downloads an account's list of Gaia service flags.
+class AccountServiceFlagFetcher : public GaiaAuthConsumer,

[Bernhard Bauer, 2014/05/16 08:19:38]

Gaia account maybe? This is very specific to Gaia.

[Marc Treib, 2014/05/20 10:46:40]

Drew, WDYT? "Account" is used as a synonym for "Gaia account" in other places as
well, e.g. components/signin/core/browser/account_reconcilor.

[Bernhard Bauer, 2014/05/20 12:35:27]

Oh, right. OK, if account in here means Gaia account, it's fine with me.

+                                  public OAuth2TokenService::Observer,
+                                  public OAuth2TokenService::Consumer {
+ public:
+  // Callback for Start() below. If the flag download is successful, this will
+  // return the list of service flags that are set for the primary account.
+  typedef base::Callback<void(const std::vector<std::string>& /* flags */)>

[Andrew T Wilson (Slow), 2014/05/16 08:44:44]

What do you do in case of error?

[Marc Treib, 2014/05/20 10:46:40]

I've added a status enum to the callback to report errors. This seems sufficient
here, and it's simpler than a separate callback or a listener interface.

+      Callback;
+
+  explicit AccountServiceFlagFetcher(Profile* profile);

[Andrew T Wilson (Slow), 2014/05/16 08:44:44]

Please put this in components/signin. To do this, you'll need to change this
class to not pass in a Profile but to instead to pass in your RequestContext,
PO2TS and SigninManager directly.

[Marc Treib, 2014/05/20 10:46:40]

Done. The SigninManager actually isn't required, it's enough to pass in the
account id.

+  virtual ~AccountServiceFlagFetcher();
+
+  // Starts fetching the flags. Must not be called again while a previous call
+  // is still pending. The callback will be called iff the flags are
+  // successfully fetched.
+  void Start(const Callback& callback);
+
+  // Cancels the pending request (if any).
+  void Cancel();

[Andrew T Wilson (Slow), 2014/05/16 08:44:44]

Do you have to call Cancel() before destroying the object? If not, then maybe we
shouldn't even expose Cancel() but instead just have callers destroy the object
if they want to cancel calls?

Then you could have a static API that both creates an AccountServiceFlagFetcher
and also Start()s it - this makes the class single-use-only, and avoids this
icky situation of callers having to worry about whether there's already a
pending call.

[Marc Treib, 2014/05/20 10:46:40]

Okay, now the constructor immediately starts the request - I like to keep the
ctor-dtor symmetry, as opposed to a static CreateAndStart function, and then
having a private ctor and public dtor.

+
+  // Returns whether a previous call to Start() is still pending.
+  bool IsPending() const;
+
+ private:
+  void StartFetchingOAuth2AccessToken(const std::string& account_id);
+
+  // Overridden from OAuth2TokenService::Observer:
+  virtual void OnRefreshTokenAvailable(const std::string& account_id) OVERRIDE;
+
+  // Overridden from OAuth2TokenService::Consumer:
+  virtual void OnGetTokenSuccess(const OAuth2TokenService::Request* request,
+                                 const std::string& access_token,
+                                 const base::Time& expiration_time) OVERRIDE;
+  virtual void OnGetTokenFailure(const OAuth2TokenService::Request* request,
+                                 const GoogleServiceAuthError& error) OVERRIDE;
+
+  // Overridden from GaiaAuthConsumer:
+  virtual void OnClientLoginSuccess(const ClientLoginResult& result) OVERRIDE;
+  virtual void OnClientLoginFailure(const GoogleServiceAuthError& error)
+      OVERRIDE;
+  virtual void OnGetUserInfoSuccess(const UserInfoMap& data) OVERRIDE;
+  virtual void OnGetUserInfoFailure(const GoogleServiceAuthError& error)
+      OVERRIDE;
+
+  Profile* profile_;
+
+  Callback callback_;
+
+  scoped_ptr<OAuth2TokenService::Request> oauth2_access_token_request_;
+  GaiaAuthFetcher gaia_auth_fetcher_;
+};
+
+#endif  // CHROME_BROWSER_SIGNIN_ACCOUNT_SERVICE_FLAG_FETCHER_H_