Send metrics with embedded system profiles after system startup.

components/metrics/metrics_service.h

Index: components/metrics/metrics_service.h
diff --git a/components/metrics/metrics_service.h b/components/metrics/metrics_service.h
index f95fd6d7f97a182d755d5c1a2e825a83d1cd4daa..79a241f31033db03b9256e5817a2c4f4e6110e4a 100644
--- a/components/metrics/metrics_service.h
+++ b/components/metrics/metrics_service.h
@@ -353,6 +353,15 @@ class MetricsService : public base::HistogramFlattener {
   // i.e., histograms with the |kUmaStabilityHistogramFlag| flag set.
   void RecordCurrentStabilityHistograms();
 
+  // Record a single independent profile and assocatied histogram from
+  // metrics providers. If this returns true, one was found and there may
+  // be more.
+  bool RecordIndependentHistogramLog();

[Alexei Svitkine (slow), 2017/06/08 23:59:31]

Nit: I find the names not very clear. First, I suggest using the "Prepare"
terminology to match PrepareInitialStabilityLog(). "Record" is usually used when
we record metrics (i.e. functions that have histogram macros in them).

Also, I think mentioning that this is from the providers in the name would be
good. e.g. PrepareProviderMetricsLog().

[bcwhite, 2017/06/09 15:09:27]

Done.

+
+  // Records one independent histogram log and then reschedules itself to
+  // check for others. The interval is so as to not adversely impact the UI.
+  void RecordIndependentHistogramJob();

[Alexei Svitkine (slow), 2017/06/08 23:59:31]

Nit: Job -> Task, so with the above suggestion PrepareProviderMetricsLogTask().

[bcwhite, 2017/06/09 15:09:27]

Done.

+
   // Sub-service for uploading logs.
   MetricsReportingService reporting_service_;