Implement UMA log throttling for cellular connections

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 ce4102b8dfa36408fe037bd6772184d759a48a4e..68184503771608756d700ca482a76231af50b923 100644
--- a/components/metrics/metrics_service.h
+++ b/components/metrics/metrics_service.h
@@ -27,6 +27,7 @@
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "components/metrics/clean_exit_beacon.h"
+#include "components/metrics/data_use_tracker.h"
 #include "components/metrics/metrics_log.h"
 #include "components/metrics/metrics_log_manager.h"
 #include "components/metrics/metrics_provider.h"
@@ -79,7 +80,8 @@ class MetricsService : public base::HistogramFlattener {
   // for the lifetime of this class.
   MetricsService(MetricsStateManager* state_manager,
                  MetricsServiceClient* client,
-                 PrefService* local_state);
+                 PrefService* local_state,
+                 base::Callback<void(bool*)> cellular_callback);
   ~MetricsService() override;
 
   // Initializes metrics recording state. Updates various bookkeeping values in
@@ -214,6 +216,8 @@ class MetricsService : public base::HistogramFlattener {
   // Pushes a log that has been generated by an external component.
   void PushExternalLog(const std::string& log);
 
+  base::WeakPtr<DataUseTracker> GetDataUseTracker();
+
  protected:
   // Exposed for testing.
   MetricsLogManager* log_manager() { return &log_manager_; }
@@ -468,10 +472,16 @@ class MetricsService : public base::HistogramFlattener {
   // Execution phase the browser is in.
   static ExecutionPhase execution_phase_;
 
-  // Reduntant marker to check that we completed our shutdown, and set the
+  // Redundant marker to check that we completed our shutdown, and set the
   // exited-cleanly bit in the prefs.
   static ShutdownCleanliness clean_shutdown_status_;
 
+  // Returns true if current connection type is cellular and user is assigned to
+  // experimental group for enabled cellular uploads.
+  base::Callback<void(bool*)> cellular_callback_;

[Alexei Svitkine (slow), 2016/03/29 16:29:10]

Put these members below the friend declarations.

[gayane -on leave until 09-2017, 2016/03/31 01:38:24]

Done.

+
+  scoped_ptr<DataUseTracker> data_use_tracker_;
+
   FRIEND_TEST_ALL_PREFIXES(MetricsServiceTest, IsPluginProcess);
   FRIEND_TEST_ALL_PREFIXES(MetricsServiceTest,
                            PermutedEntropyCacheClearedWhenLowEntropyReset);