Implement UMA log throttling for cellular connections

components/metrics/metrics_service_unittest.cc

Index: components/metrics/metrics_service_unittest.cc
diff --git a/components/metrics/metrics_service_unittest.cc b/components/metrics/metrics_service_unittest.cc
index 4a8aea770e9f7feb3bdd64239885d2ca4e9321a0..18a9756c1acafe06f6b5a815310353fb422a4a72 100644
--- a/components/metrics/metrics_service_unittest.cc
+++ b/components/metrics/metrics_service_unittest.cc
@@ -29,6 +29,13 @@
 namespace metrics {
 
 namespace {

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

Add an empty line below.

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

Done.

+bool IsCellularEnabled() {
+  return false;
+}
+
+const base::Callback<bool(void)> GetCellularCallback() {
+  return base::Bind(&IsCellularEnabled);
+}
 
 void StoreNoClientInfoBackup(const ClientInfo& /* client_info */) {
 }
@@ -42,7 +49,10 @@ class TestMetricsService : public MetricsService {
   TestMetricsService(MetricsStateManager* state_manager,
                      MetricsServiceClient* client,
                      PrefService* local_state)
-      : MetricsService(state_manager, client, local_state) {}
+      : MetricsService(state_manager,
+                       client,
+                       local_state,
+                       GetCellularCallback()) {}
   ~TestMetricsService() override {}
 
   using MetricsService::log_manager;
@@ -315,7 +325,8 @@ TEST_F(MetricsServiceTest, InitialStabilityLogAfterCrash) {
 
 TEST_F(MetricsServiceTest, RegisterSyntheticTrial) {
   TestMetricsServiceClient client;
-  MetricsService service(GetMetricsStateManager(), &client, GetLocalState());
+  MetricsService service(GetMetricsStateManager(), &client, GetLocalState(),
+                         GetCellularCallback());
 
   // Add two synthetic trials and confirm that they show up in the list.
   variations::SyntheticTrialGroup trial1(HashName("TestTrial1"),