Record the time since Chromium is in background for background data use

components/data_use_measurement/content/data_use_measurement.h

 // 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.
 
 #ifndef COMPONENTS_DATA_USE_MEASUREMENT_CONTENT_DATA_USE_MEASUREMENT_H_
 #define COMPONENTS_DATA_USE_MEASUREMENT_CONTENT_DATA_USE_MEASUREMENT_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/callback.h"
 #include "base/macros.h"
+#include "base/time/time.h"
 #include "build/build_config.h"
 #include "components/data_use_measurement/core/data_use_user_data.h"
 #include "components/metrics/data_use_tracker.h"
 
 #if defined(OS_ANDROID)
 #include "base/android/application_status_listener.h"
 #endif
 
 class GURL;
 
@@ skipping 35 matching lines @@
 
 #if defined(OS_ANDROID)
   // This function should just be used for testing purposes. A change in
   // application state can be simulated by calling this function.
   void OnApplicationStateChangeForTesting(
       base::android::ApplicationState application_state);
 #endif
 
  private:
   friend class DataUseMeasurementTest;
+  FRIEND_TEST_ALL_PREFIXES(DataUseMeasurementTest,
+                           TimeOfBackgroundDownstreamBytes);
 
   // Specifies that data is received or sent, respectively.
   enum TrafficDirection { DOWNSTREAM, UPSTREAM };
 
   // Returns the current application state (Foreground or Background). It always
   // returns Foreground if Chrome is not running on Android.
   DataUseUserData::AppState CurrentAppState() const;
 
   // Makes the full name of the histogram. It is made from |prefix| and suffix
   // which is made based on network and application status. suffix is a string
@@ skipping 16 matching lines @@
 
   // Records the count of bytes received and sent by Chrome on the network as
   // reported by the operating system.
   void MaybeRecordNetworkBytesOS();
 #endif
 
   // Records the data use of the |request|, thus |request| must be non-null.
   // |dir| is the direction (which is upstream or downstream) and |bytes| is the
   // number of bytes in the direction.
   void ReportDataUseUMA(const net::URLRequest& request,
-                                       TrafficDirection dir,
-                                       int64_t bytes) const;
+                        TrafficDirection dir,
+                        int64_t bytes);
 
   // Updates the data use of the |request|, thus |request| must be non-null.
   void UpdateDataUsePrefs(const net::URLRequest& request) const;
 
   // A helper function used to record data use of services. It gets the size of
   // 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.
   // |app_state| indicates the app state which can be foreground, background, or
   // unknown.
@@ skipping 22 matching lines @@
   // Number of bytes received and sent by Chromium as reported by the operating
   // system when it was last queried for traffic statistics. Set to 0 if the
   // operating system was never queried.
   int64_t rx_bytes_os_;
   int64_t tx_bytes_os_;
 
   // Number of bytes received and sent by Chromium as reported by the network
   // delegate since the operating system was last queried for traffic
   // statistics.
   int64_t bytes_transferred_since_last_traffic_stats_query_;
+
+  // The time at which Chromium app state changed to background. Can be null if
+  // app is not in background.
+  base::TimeTicks last_app_background_time_;
+
+  // True if app is in background and first network read has not yet happened.
+  bool no_reads_since_background_;
 #endif
 
   DISALLOW_COPY_AND_ASSIGN(DataUseMeasurement);
 };
 
 }  // namespace data_use_measurement
 
 #endif  // COMPONENTS_DATA_USE_MEASUREMENT_CONTENT_DATA_USE_MEASUREMENT_H_