Revert 148792 - [Sync] Remove CleanupDisabledTypes command and move purge logic into SyncManager.

sync/engine/sync_scheduler_impl.h

 // Copyright (c) 2012 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 SYNC_ENGINE_SYNC_SCHEDULER_IMPL_H_
 #define SYNC_ENGINE_SYNC_SCHEDULER_IMPL_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 81 matching lines @@
     enum SyncSessionJobPurpose {
       // Uninitialized state, should never be hit in practice.
       UNKNOWN = -1,
       // Our poll timer schedules POLL jobs periodically based on a server
       // assigned poll interval.
       POLL,
       // A nudge task can come from a variety of components needing to force
       // a sync.  The source is inferable from |session.source()|.
       NUDGE,
       // Typically used for fetching updates for a subset of the enabled types
-      // during initial sync or reconfiguration.
+      // during initial sync or reconfiguration.  We don't run all steps of
+      // the sync cycle for these (e.g. CleanupDisabledTypes is skipped).
       CONFIGURATION,
+      // The user disabled some types and we have to clean up the data
+      // for those.
+      CLEANUP_DISABLED_TYPES,
     };
     SyncSessionJob();
     SyncSessionJob(SyncSessionJobPurpose purpose, base::TimeTicks start,
         linked_ptr<sessions::SyncSession> session, bool is_canary_job,
         const ConfigurationParams& config_params,
         const tracked_objects::Location& nudge_location);
     ~SyncSessionJob();
     static const char* GetPurposeString(SyncSessionJobPurpose purpose);
 
     SyncSessionJobPurpose purpose;
@@ skipping 95 matching lines @@
   // Helper to assemble a job and post a delayed task to sync.
   void ScheduleSyncSessionJob(const SyncSessionJob& job);
 
   // Invoke the Syncer to perform a sync.
   void DoSyncSessionJob(const SyncSessionJob& job);
 
   // Called after the Syncer has performed the sync represented by |job|, to
   // reset our state.
   void FinishSyncSessionJob(const SyncSessionJob& job);
 
+  // Record important state that might be needed in future syncs, such as which
+  // data types may require cleanup.
+  void UpdateCarryoverSessionState(const SyncSessionJob& old_job);
+
   // Helper to FinishSyncSessionJob to schedule the next sync operation.
   void ScheduleNextSync(const SyncSessionJob& old_job);
 
   // Helper to configure polling intervals. Used by Start and ScheduleNextSync.
   void AdjustPolling(const SyncSessionJob* old_job);
 
   // Helper to restart waiting with |wait_interval_|'s timer.
   void RestartWaiting();
 
   // Helper to ScheduleNextSync in case of consecutive sync errors.
@@ skipping 114 matching lines @@
   scoped_ptr<Syncer> syncer_;
 
   sessions::SyncSessionContext *session_context_;
 
   DISALLOW_COPY_AND_ASSIGN(SyncSchedulerImpl);
 };
 
 }  // namespace syncer
 
 #endif  // SYNC_ENGINE_SYNC_SCHEDULER_IMPL_H_