Fix foregound vs background data use measurement

components/data_use_measurement/content/data_use_measurement.h

Index: components/data_use_measurement/content/data_use_measurement.h
diff --git a/components/data_use_measurement/content/data_use_measurement.h b/components/data_use_measurement/content/data_use_measurement.h
index c115dc4bf27927ee2d8adc74b078b3d4ee0a26ba..f035ce4ace8afa08147ca3ca2732225c2bc3025f 100644
--- a/components/data_use_measurement/content/data_use_measurement.h
+++ b/components/data_use_measurement/content/data_use_measurement.h
@@ -40,6 +40,9 @@ class DataUseMeasurement {
       const metrics::UpdateUsagePrefCallbackType& metrics_data_use_forwarder);
   ~DataUseMeasurement();
 
+  // Called before a request is sent.
+  void OnBeforeURLRequest(net::URLRequest* request);
+
   // Called right after a redirect response code was received for |request|.
   void OnBeforeRedirect(const net::URLRequest& request,
                         const GURL& new_location);
@@ -58,6 +61,8 @@ class DataUseMeasurement {
 #endif
 
  private:
+  friend class DataUseMeasurementTest;
+
   // Specifies that data is received or sent, respectively.
   enum TrafficDirection { DOWNSTREAM, UPSTREAM };
 
@@ -75,8 +80,11 @@ class DataUseMeasurement {
   // ("Downstream") path, whether the app was in the "Foreground" or
   // "Background", and whether a "Cellular" or "WiFi" network was use. For
   // example, "Prefix.Upstream.Foreground.Cellular" is a possible output.
+  // |started_in_foreground| indicates if the request started when the app was
+  // in foreground.
   std::string GetHistogramName(const char* prefix,
                                TrafficDirection dir,
+                               bool started_in_foreground,
                                bool is_connection_cellular) const;
 
 #if defined(OS_ANDROID)
@@ -93,9 +101,12 @@ class DataUseMeasurement {
   // exchanged message, its direction (which is upstream or downstream) and
   // reports to two histogram groups. DataUse.MessageSize.ServiceName and
   // DataUse.Services.{Dimensions}. In the second one, services are buckets.
+  // |started_in_foreground| indicates if the request started when the app was
+  // in foreground.
   void ReportDataUsageServices(
       data_use_measurement::DataUseUserData::ServiceName service,
       TrafficDirection dir,
+      bool started_in_foreground,
       bool is_connection_cellular,
       int64_t message_size) const;