[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 token reporting.
+  void ScheduleReportTokens();
   // 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 reporting.
+  base::TimeDelta GetTimeToNextTokenReporting() 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_;
 
+  // Creates weak pointers used to postpone reporting tokens. See
+  // ScheduleReportTokens.
+  base::WeakPtrFactory<GCMAccountTracker> reporting_weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(GCMAccountTracker);
 };
 
 }  // namespace gcm
 
 #endif  // CHROME_BROWSER_SERVICES_GCM_GCM_ACCOUNT_TRACKER_H_