sync: Refactor job ownership in SyncScheduler

sync/engine/sync_session_job.cc

 // 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.
 
 #include "sync/engine/sync_session_job.h"
 #include "sync/internal_api/public/sessions/model_neutral_state.h"
 
 namespace syncer {
 
 SyncSessionJob::~SyncSessionJob() {
 }
 
 SyncSessionJob::SyncSessionJob(
     Purpose purpose,
     base::TimeTicks start,
     const sessions::SyncSourceInfo& source_info,
     const ConfigurationParams& config_params)
     : purpose_(purpose),
       source_info_(source_info),
       scheduled_start_(start),
-      config_params_(config_params),
-      finished_(NOT_FINISHED) {
+      config_params_(config_params) {
 }
 
 #define ENUM_CASE(x) case x: return #x; break;
 const char* SyncSessionJob::GetPurposeString(SyncSessionJob::Purpose purpose) {
   switch (purpose) {
     ENUM_CASE(UNKNOWN);
     ENUM_CASE(POLL);
     ENUM_CASE(NUDGE);
     ENUM_CASE(CONFIGURATION);
   }
   NOTREACHED();
   return "";
 }
 #undef ENUM_CASE
 
 bool SyncSessionJob::Finish(bool early_exit, sessions::SyncSession* session) {
-  DCHECK_EQ(finished_, NOT_FINISHED);
-  // Did we run through all SyncerSteps from start_step() to end_step()
-  // until the SyncSession returned !HasMoreToSync()?
-  // Note: if not, it's possible the scheduler hasn't started with
-  // SyncShare yet, it's possible there is still more to sync in the session,
-  // and it's also possible the job quit part way through due to a premature
-  // exit condition (such as shutdown).
-  finished_ = early_exit ? EARLY_EXIT : FINISHED;
-
+  // Did we quit part-way through due to premature exit condition, like
+  // shutdown?  Note that this branch will not be hit for other kinds
+  // of early return scenarios, like certain kinds of transient errors.
   if (early_exit)
     return false;
 
   // Did we hit any errors along the way?
   if (sessions::HasSyncerError(
       session->status_controller().model_neutral_state())) {
     return false;
   }
 
   const sessions::ModelNeutralState& state(
@@ skipping 10 matching lines @@
     case UNKNOWN:
     default:
       NOTREACHED();
   }
 
   if (!config_params_.ready_task.is_null())
     config_params_.ready_task.Run();
   return true;
 }
 
-scoped_ptr<SyncSessionJob> SyncSessionJob::Clone() const {
-  return scoped_ptr<SyncSessionJob>(new SyncSessionJob(
-      purpose_, scheduled_start_, source_info_,
-      config_params_));
-}
-
 void SyncSessionJob::CoalesceSources(const sessions::SyncSourceInfo& source) {
   CoalesceStates(source.types, &source_info_.types);
   source_info_.updates_source = source.updates_source;
 }
 
 SyncSessionJob::Purpose SyncSessionJob::purpose() const {
   return purpose_;
 }
 
 const sessions::SyncSourceInfo& SyncSessionJob::source_info() const {
@@ skipping 40 matching lines @@
       return;
     default:
       NOTREACHED();
       *start = SYNCER_END;
       *end = SYNCER_END;
       return;
   }
 }
 
 }  // namespace syncer