[Sync] Add client-side plumbing for server control of sessions commit delay

chrome/browser/sync/engine/sync_scheduler.h

 // Copyright (c) 2011 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.
 //
 // A class to schedule syncer tasks intelligently.
 #ifndef CHROME_BROWSER_SYNC_ENGINE_SYNC_SCHEDULER_H_
 #define CHROME_BROWSER_SYNC_ENGINE_SYNC_SCHEDULER_H_
 #pragma once
 
 #include <string>
 
 #include "base/callback.h"
+#include "base/compiler_specific.h"
 #include "base/gtest_prod_util.h"
 #include "base/memory/linked_ptr.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/observer_list.h"
 #include "base/task.h"
 #include "base/time.h"
 #include "base/timer.h"
 #include "chrome/browser/sync/engine/configure_reason.h"
 #include "chrome/browser/sync/engine/nudge_source.h"
 #include "chrome/browser/sync/engine/polling_constants.h"
@@ skipping 68 matching lines @@
       const syncable::ModelTypePayloadMap& types_with_payloads,
       const tracked_objects::Location& nudge_location);
   void ScheduleConfig(const syncable::ModelTypeBitSet& types,
       sync_api::ConfigureReason reason);
   void ScheduleClearUserData();
   void ScheduleCleanupDisabledTypes();
 
   // Change status of notifications in the SyncSessionContext.
   void set_notifications_enabled(bool notifications_enabled);
 
+  base::TimeDelta GetSessionsCommitDelay() const;
+
   // DDOS avoidance function.  Calculates how long we should wait before trying
   // again after a failed sync attempt, where the last delay was |base_delay|.
   // TODO(tim): Look at URLRequestThrottlerEntryInterface.
   static base::TimeDelta GetRecommendedDelay(const base::TimeDelta& base_delay);
 
   // SyncSession::Delegate implementation.
-  virtual void OnSilencedUntil(const base::TimeTicks& silenced_until);
-  virtual bool IsSyncingCurrentlySilenced();
+  virtual void OnSilencedUntil(
+      const base::TimeTicks& silenced_until) OVERRIDE;
+  virtual bool IsSyncingCurrentlySilenced() OVERRIDE;
   virtual void OnReceivedShortPollIntervalUpdate(
-      const base::TimeDelta& new_interval);
+      const base::TimeDelta& new_interval) OVERRIDE;
   virtual void OnReceivedLongPollIntervalUpdate(
-      const base::TimeDelta& new_interval);
-  virtual void OnShouldStopSyncingPermanently();
+      const base::TimeDelta& new_interval) OVERRIDE;
+  virtual void OnReceivedSessionsCommitDelay(
+      const base::TimeDelta& new_delay) OVERRIDE;
+  virtual void OnShouldStopSyncingPermanently() OVERRIDE;
 
   // ServerConnectionEventListener implementation.
   // TODO(tim): schedule a nudge when valid connection detected? in 1 minute?
-  virtual void OnServerConnectionEvent(const ServerConnectionEvent& event);
+  virtual void OnServerConnectionEvent(
+      const ServerConnectionEvent& event) OVERRIDE;
 
  private:
   enum JobProcessDecision {
     // Indicates we should continue with the current job.
     CONTINUE,
     // Indicates that we should save it to be processed later.
     SAVE,
     // Indicates we should drop this job.
     DROP,
   };
@@ skipping 224 matching lines @@
   MessageLoop* const sync_loop_;
 
   // Set in Start(), unset in Stop().
   bool started_;
 
   // Modifiable versions of kDefaultLongPollIntervalSeconds which can be
   // updated by the server.
   base::TimeDelta syncer_short_poll_interval_seconds_;
   base::TimeDelta syncer_long_poll_interval_seconds_;
 
+  // Server-tweakable sessions commit delay.
+  base::TimeDelta sessions_commit_delay_;
+
   // Periodic timer for polling.  See AdjustPolling.
   base::RepeatingTimer<SyncScheduler> poll_timer_;
 
   // The mode of operation.
   Mode mode_;
 
   // TODO(tim): Bug 26339. This needs to track more than just time I think,
   // since the nudges could be for different types. Current impl doesn't care.
   base::TimeTicks last_sync_session_end_time_;
 
@@ skipping 12 matching lines @@
   scoped_ptr<Syncer> syncer_;
 
   scoped_ptr<sessions::SyncSessionContext> session_context_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncScheduler);
 };
 
 }  // namespace browser_sync
 
 #endif  // CHROME_BROWSER_SYNC_ENGINE_SYNC_SCHEDULER_H_