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

components/signin/core/browser/account_service_flag_fetcher.h

Index: components/signin/core/browser/account_service_flag_fetcher.h
diff --git a/components/signin/core/browser/account_service_flag_fetcher.h b/components/signin/core/browser/account_service_flag_fetcher.h
new file mode 100644
index 0000000000000000000000000000000000000000..44310909c1c607fb6b13e0a5ad3ef19d1fa08930
--- /dev/null
+++ b/components/signin/core/browser/account_service_flag_fetcher.h
@@ -0,0 +1,78 @@
+// 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_SIGNIN_CORE_BROWSER_ACCOUNT_SERVICE_FLAG_FETCHER_H_
+#define COMPONENTS_SIGNIN_CORE_BROWSER_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 ProfileOAuth2TokenService;
+
+namespace net {
+class URLRequestContextGetter;
+}
+
+// Downloads an account's list of Gaia service flags.

[Andrew T Wilson (Slow), 2014/05/23 14:51:59]

Can you add a bit of information about how to use this class? You have
documentation below on the constructor/destructor that talks about how they
start/stop the fetch, but it'd be nice to talk about that up here at the class
level.

[Marc Treib, 2014/05/26 12:31:40]

Done.

+class AccountServiceFlagFetcher : public GaiaAuthConsumer,
+                                  public OAuth2TokenService::Observer,
+                                  public OAuth2TokenService::Consumer {
+ public:
+  enum ResultCode {
+    SUCCESS,
+    TOKEN_ERROR,    // Failed to get OAuth2 token.
+    SERVICE_ERROR,  // Service returned an error or malformed reply.
+  };
+  // If the flag download is successful, this will return the list of service

[Andrew T Wilson (Slow), 2014/05/23 14:51:59]

nit: blank line above

[Marc Treib, 2014/05/26 12:31:40]

Done.

+  // flags that are set for the given account.
+  typedef base::Callback<void(ResultCode /* result */,
+                              const std::vector<std::string>& /* flags */)>
+      Callback;

[Andrew T Wilson (Slow), 2014/05/23 14:51:59]

This is OK, I guess, except you're now hiding base::Callback. Can you name this
something else (like ServiceFlagResultCallback or something like that)?

[Marc Treib, 2014/05/26 12:31:40]

I called it "ResultCallback"; I think the "ServiceFlag" is implicit since it's a
member of AccountServiceFlagFetcher.

+
+  // Immediately starts fetching the flags.
+  AccountServiceFlagFetcher(const std::string& account_id,
+                            ProfileOAuth2TokenService* token_service,
+                            net::URLRequestContextGetter* request_context,
+                            const Callback& callback);
+  // Destructing the object before the callback is called cancels the request.

[Andrew T Wilson (Slow), 2014/05/23 14:51:59]

nit: blank line above

[Marc Treib, 2014/05/26 12:31:40]

Done.

+  virtual ~AccountServiceFlagFetcher();
+
+ private:
+  void Start();
+  void StartFetchingOAuth2AccessToken();
+
+  // 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;
+
+  const std::string account_id_;
+  ProfileOAuth2TokenService* token_service_;
+  GaiaAuthFetcher gaia_auth_fetcher_;
+
+  Callback callback_;
+
+  scoped_ptr<OAuth2TokenService::Request> oauth2_access_token_request_;
+};
+
+#endif  // COMPONENTS_SIGNIN_CORE_BROWSER_ACCOUNT_SERVICE_FLAG_FETCHER_H_