Standardize persisted log loading

components/metrics/metrics_service.cc

Index: components/metrics/metrics_service.cc
diff --git a/components/metrics/metrics_service.cc b/components/metrics/metrics_service.cc
index 797ec70fdc09d959ec804e018d67d2070b4675c0..ae2c80ff46cd6ad446d64c35565985951db2c760 100644
--- a/components/metrics/metrics_service.cc
+++ b/components/metrics/metrics_service.cc
@@ -557,6 +557,8 @@ void MetricsService::InitializeMetricsState() {
   local_state_->SetInt64(metrics::prefs::kStabilityStatsBuildTime,
                          MetricsLog::GetBuildTime());
 
+  log_manager_.LoadPersistedUnsentLogs();
+
   session_id_ = local_state_->GetInteger(metrics::prefs::kMetricsSessionID);
 
   if (!local_state_->GetBoolean(metrics::prefs::kStabilityExitedCleanly)) {
@@ -741,8 +743,7 @@ void MetricsService::CloseCurrentLog() {
   // end of all log transmissions (initial log handles this separately).
   // RecordIncrementalStabilityElements only exists on the derived
   // MetricsLog class.
-  MetricsLog* current_log =
-      static_cast<MetricsLog*>(log_manager_.current_log());
+  MetricsLog* current_log = log_manager_.current_log();
   DCHECK(current_log);
   std::vector<variations::ActiveGroupId> synthetic_trials;
   GetCurrentSyntheticFieldTrials(&synthetic_trials);
@@ -888,13 +889,9 @@ void MetricsService::StageNewLog() {
         // There's an initial stability log, ready to send.
         log_manager_.StageNextLogForUpload();
         has_initial_stability_log_ = false;
-        // Note: No need to call LoadPersistedUnsentLogs() here because unsent
-        // logs have already been loaded by PrepareInitialStabilityLog().
         state_ = SENDING_INITIAL_STABILITY_LOG;
       } else {
         PrepareInitialMetricsLog();
-        // Load unsent logs (if any) from local state.
-        log_manager_.LoadPersistedUnsentLogs();
         state_ = SENDING_INITIAL_METRICS_LOG;
       }
       break;
@@ -930,8 +927,6 @@ void MetricsService::PrepareInitialStabilityLog() {
   if (!initial_stability_log->LoadSavedEnvironmentFromPrefs())
     return;
 
-  log_manager_.LoadPersistedUnsentLogs();
-
   log_manager_.PauseCurrentLog();
   log_manager_.BeginLoggingWithLog(initial_stability_log.Pass());
 
@@ -973,8 +968,7 @@ void MetricsService::PrepareInitialMetricsLog() {
 
   // Note: Some stability providers may record stability stats via histograms,
   //       so this call has to be after BeginLoggingWithLog().
-  MetricsLog* current_log =
-      static_cast<MetricsLog*>(log_manager_.current_log());
+  MetricsLog* current_log = log_manager_.current_log();
   current_log->RecordStabilityMetrics(metrics_providers_.get(),
                                       base::TimeDelta(), base::TimeDelta());
   RecordCurrentHistograms();
@@ -984,6 +978,10 @@ void MetricsService::PrepareInitialMetricsLog() {
   log_manager_.FinishCurrentLog();
   log_manager_.ResumePausedLog();
 
+  // Store unsent logs, including the initial log that was just saved, so
+  // that they're not lost in case of a crash before upload time.
+  log_manager_.PersistUnsentLogs();
+
   DCHECK(!log_manager_.has_staged_log());
   log_manager_.StageNextLogForUpload();
 }
@@ -1047,31 +1045,26 @@ void MetricsService::OnLogUploadComplete(int response_code) {
     discard_log = true;
   }
 
-  if (upload_succeeded || discard_log)
+  if (upload_succeeded || discard_log) {
     log_manager_.DiscardStagedLog();
+    // Store the updated list to disk now that the removed log is uploaded.
+    log_manager_.PersistUnsentLogs();
+  }
 
   if (!log_manager_.has_staged_log()) {
     switch (state_) {
       case SENDING_INITIAL_STABILITY_LOG:
-        // Store the updated list to disk now that the removed log is uploaded.
-        log_manager_.PersistUnsentLogs();
         PrepareInitialMetricsLog();
         SendStagedLog();
         state_ = SENDING_INITIAL_METRICS_LOG;
         break;
 
       case SENDING_INITIAL_METRICS_LOG:
-        // The initial metrics log never gets persisted to local state, so it's
-        // not necessary to call log_manager_.PersistUnsentLogs() here.
-        // TODO(asvitkine): It should be persisted like the initial stability
-        // log and old unsent logs. http://crbug.com/328417
         state_ = log_manager_.has_unsent_logs() ? SENDING_OLD_LOGS
                                                 : SENDING_CURRENT_LOGS;
         break;
 
       case SENDING_OLD_LOGS:
-        // Store the updated list to disk now that the removed log is uploaded.
-        log_manager_.PersistUnsentLogs();
         if (!log_manager_.has_unsent_logs())
           state_ = SENDING_CURRENT_LOGS;
         break;
@@ -1151,8 +1144,7 @@ void MetricsService::GetCurrentSyntheticFieldTrials(
     std::vector<variations::ActiveGroupId>* synthetic_trials) {
   DCHECK(synthetic_trials);
   synthetic_trials->clear();
-  const MetricsLog* current_log =
-      static_cast<const MetricsLog*>(log_manager_.current_log());
+  const MetricsLog* current_log = log_manager_.current_log();
   for (size_t i = 0; i < synthetic_trial_groups_.size(); ++i) {
     if (synthetic_trial_groups_[i].start_time <= current_log->creation_time())
       synthetic_trials->push_back(synthetic_trial_groups_[i].id);