Make MetricsService save compressed logs to local state.

components/metrics/metrics_log_manager.cc

Index: components/metrics/metrics_log_manager.cc
===================================================================
--- components/metrics/metrics_log_manager.cc	(revision 275859)
+++ components/metrics/metrics_log_manager.cc	(working copy)
@@ -43,11 +43,13 @@
     : unsent_logs_loaded_(false),
       initial_log_queue_(local_state,
                          prefs::kMetricsInitialLogs,
+                         prefs::kMetricsInitialLogsOld,
                          kInitialLogsPersistLimit,
                          kStorageByteLimitPerLogType,
                          0),
       ongoing_log_queue_(local_state,
                          prefs::kMetricsOngoingLogs,
+                         prefs::kMetricsOngoingLogsOld,
                          kOngoingLogsPersistLimit,
                          kStorageByteLimitPerLogType,
                          max_ongoing_log_size) {}
@@ -62,10 +64,10 @@
 void MetricsLogManager::FinishCurrentLog() {
   DCHECK(current_log_.get());
   current_log_->CloseLog();
-  std::string log_text;
-  current_log_->GetEncodedLog(&log_text);
-  if (!log_text.empty())
-    StoreLog(&log_text, current_log_->log_type());
+  std::string log_data;
+  current_log_->GetEncodedLog(&log_data);
+  if (!log_data.empty())
+    StoreLog(log_data, current_log_->log_type());
   current_log_.reset();
 }
 
@@ -101,20 +103,20 @@
   current_log_.reset(paused_log_.release());
 }
 
-void MetricsLogManager::StoreLog(std::string* log,
+void MetricsLogManager::StoreLog(const std::string& log_data,
                                  MetricsLog::LogType log_type) {
   switch (log_type) {
     case MetricsLog::INITIAL_STABILITY_LOG:
-      initial_log_queue_.StoreLog(log);
+      initial_log_queue_.StoreLog(log_data);
       break;
     case MetricsLog::ONGOING_LOG:
-      ongoing_log_queue_.StoreLog(log);
+      ongoing_log_queue_.StoreLog(log_data);
       break;
   }
 }
 
 void MetricsLogManager::StoreStagedLogAsUnsent(
-    metrics::PersistedLogs::StoreType store_type) {
+    PersistedLogs::StoreType store_type) {
   DCHECK(has_staged_log());
   if (initial_log_queue_.has_staged_log())
     initial_log_queue_.StoreStagedLogAsUnsent(store_type);