Support persistent system profiles.

components/metrics/metrics_log.cc

Index: components/metrics/metrics_log.cc
diff --git a/components/metrics/metrics_log.cc b/components/metrics/metrics_log.cc
index ac35ce396a32a8f06f1a7a7d913953cbb161e290..6b2c8bf9f797693e61bbe1664d242c237d0fba07 100644
--- a/components/metrics/metrics_log.cc
+++ b/components/metrics/metrics_log.cc
@@ -22,6 +22,7 @@
 #include "components/metrics/metrics_pref_names.h"
 #include "components/metrics/metrics_provider.h"
 #include "components/metrics/metrics_service_client.h"
+#include "components/metrics/persistent_system_profile.h"
 #include "components/metrics/proto/histogram_event.pb.h"
 #include "components/metrics/proto/system_profile.pb.h"
 #include "components/metrics/proto/user_action_event.pb.h"
@@ -302,6 +303,9 @@ std::string MetricsLog::RecordEnvironment(
   for (size_t i = 0; i < metrics_providers.size(); ++i)
     metrics_providers[i]->ProvideSystemProfileMetrics(system_profile);
 
+  GlobalPersistentSystemProfile::GetInstance()->SetSystemProfile(
+      *system_profile);

[Alexei Svitkine (slow), 2017/05/29 19:48:32]

This causes the system profile to be converted from proto to string two times -
once in your new code and once as part of EnvironmentRecorder.

Let's not duplicate this work - please refactor this code so that we only do
this once. For example, pass a ptr to the persistent sp to the
EnvironmentRecorder object and have it call SetSystemProfileData() on it.

[bcwhite, 2017/05/29 20:56:35]

Turns out that SerializeAndRecordEnvironment returns the serialized proto.

Done.

+
   EnvironmentRecorder recorder(local_state_);
   return recorder.SerializeAndRecordEnvironmentToPrefs(*system_profile);
 }