Populate a basic SystemProfileProto in UKM.

components/ukm/ukm_service.h

Index: components/ukm/ukm_service.h
diff --git a/components/ukm/ukm_service.h b/components/ukm/ukm_service.h
index 9ffd417d54bbc5b6ae8ba505987118ae25679bec..0803a415871e7b1f50543a7ba038c3d5e672fe76 100644
--- a/components/ukm/ukm_service.h
+++ b/components/ukm/ukm_service.h
@@ -15,6 +15,7 @@
 #include "build/build_config.h"
 #include "components/metrics/metrics_reporting_scheduler.h"
 #include "components/metrics/persisted_logs.h"
+#include "components/metrics/proto/ukm/report.pb.h"
 
 class PrefRegistrySimple;
 class PrefService;
@@ -59,6 +60,8 @@ class UkmService : public base::SupportsWeakPtr<UkmService> {
   static void RegisterPrefs(PrefRegistrySimple* registry);
 
  private:
+  FRIEND_TEST_ALL_PREFIXES(UkmServiceTest, PopulateSystemProfile);
+
   // Start metrics client initialization.
   void StartInitTask();
 
@@ -79,6 +82,9 @@ class UkmService : public base::SupportsWeakPtr<UkmService> {
   // Called by log_uploader_ when the an upload is completed.
   void OnLogUploadComplete(int response_code);
 
+  // Populate system information (version, channel, etc.) in the Report.
+  void PopulateSystemProfile(Report* report);
+
   // A weak pointer to the PrefService used to read and write preferences.
   PrefService* pref_service_;