[GCM] Fetching OAuth2 tokens periodically in account tracker

chrome/browser/services/gcm/gcm_account_tracker.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_SERVICES_GCM_GCM_ACCOUNT_TRACKER_H_
 #define CHROME_BROWSER_SERVICES_GCM_GCM_ACCOUNT_TRACKER_H_
 
 #include <map>
 #include <string>
 
 #include "base/memory/scoped_vector.h"
 #include "components/gcm_driver/gcm_client.h"
 #include "components/gcm_driver/gcm_connection_observer.h"
 #include "google_apis/gaia/account_tracker.h"
 #include "google_apis/gaia/oauth2_token_service.h"
 
+namespace base {
+class Time;
+}
+
 namespace gcm {
 
 class GCMDriver;
 
 // Class for reporting back which accounts are signed into. It is only meant to
 // be used when the user is signed into sync.
+//
+// This class makes a check for tokens periodically, to make sure the user is
+// still logged into the profile, so that in the case that the user is not, we
+// can immediately report that to the GCM and stop messages addressed to that
+// user from ever reaching Chrome.
 class GCMAccountTracker : public gaia::AccountTracker::Observer,
                           public OAuth2TokenService::Consumer,
                           public GCMConnectionObserver {
  public:
   // State of the account.
   // Allowed transitions:
   // TOKEN_NEEDED - account info was created.
   // TOKEN_NEEDED -> GETTING_TOKEN - access token was requested.
   // GETTING_TOKEN -> TOKEN_NEEDED - access token fetching failed.
   // GETTING_TOKEN -> TOKEN_PRESENT - access token fetching succeeded.
@@ skipping 36 matching lines @@
 
   // Starts tracking accounts.
   void Start();
 
   // Gets the number of pending token requests. Only used for testing.
   size_t get_pending_token_request_count() const {
     return pending_token_requests_.size();
   }
 
  private:
+  friend class GCMAccountTrackerTest;
+
   // Maps account keys to account states. Keyed by account_ids as used by
   // OAuth2TokenService.
   typedef std::map<std::string, AccountInfo> AccountInfos;
 
   // AccountTracker::Observer overrides.
   void OnAccountAdded(const gaia::AccountIds& ids) override;
   void OnAccountRemoved(const gaia::AccountIds& ids) override;
   void OnAccountSignInChanged(const gaia::AccountIds& ids,
                               bool is_signed_in) override;
 
   // OAuth2TokenService::Consumer overrides.
   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;
 
   // GCMConnectionObserver overrides.
   void OnConnected(const net::IPEndPoint& ip_endpoint) override;
   void OnDisconnected() override;
 
+  // Schedules fetching tokens at the time when they are needed to be reported.

[Nicolas Zea, 2014/11/07 22:19:25]

nit: "at the time when they are needed to be reported" -> "if new tokens are
required (see IsTokenReportingRequired)"

Also, does it make more sense to name this ScheduleReportTokens? It's kind of
strange that this is calling ReportTokens, rather than triggering Fetching. In
my mind fetching and reporting are independent things.

[fgorski, 2014/11/07 22:57:02]

Done. Restructured and renamed the GetTimeTo... as well.

+  void ScheduleFetchingTokens();
   // Report the list of accounts with OAuth2 tokens back using the |callback_|
   // function. If there are token requests in progress, do nothing.
-  void CompleteCollectingTokens();
+  void ReportTokens();
   // Verify that all of the tokens are ready to be passed down to the GCM
   // Driver, e.g. none of them has expired or is missing. Returns true if not
   // all tokens are valid and a fetching yet more tokens is required.
-  bool SanitizeTokens();
+  void SanitizeTokens();
+  // Indicates whether token reporting is required, either because it is due, or
+  // some of the accounts were removed.
+  bool IsTokenReportingRequired() const;
+  // Indicates whether there are tokens that still need fetching.
+  bool IsTokenFetchingRequired() const;
+  // Gets the time until next token fetching.
+  base::TimeDelta GetTimeToNextTokenFetching() const;
   // Deletes a token request. Should be called from OnGetTokenSuccess(..) or
   // OnGetTokenFailure(..).
   void DeleteTokenRequest(const OAuth2TokenService::Request* request);
   // Checks on all known accounts, and calls GetToken(..) for those with
   // |state == TOKEN_NEEDED|.
   void GetAllNeededTokens();
   // Starts fetching the OAuth2 token for the GCM group scope.
   void GetToken(AccountInfos::iterator& account_iter);
 
   // Handling of actual sign in and sign out for accounts.
   void OnAccountSignedIn(const gaia::AccountIds& ids);
   void OnAccountSignedOut(const gaia::AccountIds& ids);
 
   OAuth2TokenService* GetTokenService();
 
   // Account tracker.
   scoped_ptr<gaia::AccountTracker> account_tracker_;
 
   // GCM Driver. Not owned.
   GCMDriver* driver_;
 
   // State of the account.
   AccountInfos account_infos_;
 
   // Indicates whether shutdown has been called.
   bool shutdown_called_;
 
   ScopedVector<OAuth2TokenService::Request> pending_token_requests_;
 
+  base::WeakPtrFactory<GCMAccountTracker> reporting_weak_ptr_factory_;

[Nicolas Zea, 2014/11/07 22:19:25]

nit: comment that this is for ReportTokens usage.

[fgorski, 2014/11/07 22:57:02]

Done.

[Nicolas Zea, 2014/11/07 23:03:23]

Looks like this didn't make it into the patch?

[fgorski, 2014/11/07 23:29:07]

didn't :w it. Updated.

+
   DISALLOW_COPY_AND_ASSIGN(GCMAccountTracker);
 };
 
 }  // namespace gcm
 
 #endif  // CHROME_BROWSER_SERVICES_GCM_GCM_ACCOUNT_TRACKER_H_