Implement UMA log throttling for cellular connections

components/data_use_measurement/content/data_use_measurement.cc

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/data_use_measurement/content/data_use_measurement.h"
 
 #include "base/metrics/histogram.h"
 #include "base/metrics/sparse_histogram.h"
 #include "base/strings/stringprintf.h"
 #include "build/build_config.h"
@@ skipping 70 matching lines @@
                        UPSTREAM),
       total_upload_bytes);
   RecordUMAHistogramCount(
       GetHistogramName(is_user_traffic ? "DataUse.TrafficSize.User"
                                        : "DataUse.TrafficSize.System",
                        DOWNSTREAM),
       total_received_bytes);
 
   DataUseUserData* attached_service_data = reinterpret_cast<DataUseUserData*>(
       request->GetUserData(DataUseUserData::kUserDataKey));
-
+  DataUseUserData::ServiceName service_name =
+      attached_service_data ? attached_service_data->service_name()
+                            : DataUseUserData::NOT_TAGGED;
   if (!is_user_traffic) {
-    DataUseUserData::ServiceName service_name =
-        attached_service_data ? attached_service_data->service_name()
-                              : DataUseUserData::NOT_TAGGED;
     ReportDataUsageServices(service_name, UPSTREAM, total_upload_bytes);
     ReportDataUsageServices(service_name, DOWNSTREAM, total_received_bytes);
   }
+
+  // Update data use prefs for cellular connections.
+  bool is_cellular = net::NetworkChangeNotifier::IsConnectionCellular(
+      net::NetworkChangeNotifier::GetConnectionType());

[Alexei Svitkine (slow), 2016/03/31 04:32:25]

This already gets queried inside the GetHistogramName() calls above. Can you
move this up above that code and make GetHistogramName() take the boolean as a
param so this is only done once?

[gayane -on leave until 09-2017, 2016/03/31 17:54:58]

Done.

+  if (is_cellular && !metrics_data_use_forwarder_.is_null()) {
+    metrics_data_use_forwarder_.Run(
+        attached_service_data->GetServiceNameAsString(service_name),
+        total_upload_bytes + total_received_bytes);
+  }
 }
 
 #if defined(OS_ANDROID)
 void DataUseMeasurement::OnApplicationStateChangeForTesting(
     base::android::ApplicationState application_state) {
   app_state_ = application_state;
 }
 #endif
 
 DataUseMeasurement::AppState DataUseMeasurement::CurrentAppState() const {
@@ skipping 30 matching lines @@
   RecordUMAHistogramCount(
       "DataUse.MessageSize." + DataUseUserData::GetServiceNameAsString(service),
       message_size);
   if (message_size > 0) {
     IncreaseSparseHistogramByValue(
         GetHistogramName("DataUse.MessageSize.AllServices", dir), service,
         message_size);
   }
 }
 
+void DataUseMeasurement::SetMetricsDataUseForwarder(
+    metrics::UpdateUsagePrefCallbackType metrics_data_use_forwarder) {
+  metrics_data_use_forwarder_ = metrics_data_use_forwarder;
+}
+
 }  // namespace data_use_measurement