Support needed to measure user and service traffic in Chrome.

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 <string>
+
+#include "base/memory/scoped_ptr.h"
+#include "build/build_config.h"
+#include "components/data_use_measurement/core/data_use_user_data.h"
+
+#if defined(OS_ANDROID)
+#include "base/android/application_status_listener.h"
+#endif
+
+namespace net {
+class URLRequest;
+}
+
+namespace data_use_measurement {
+
+class DataUseMeasurement {
+ public:
+  // This constructor instantiate a listener object and bind its callback.
+  DataUseMeasurement();
+
+  ~DataUseMeasurement();
+
+  // Records the data use of the |request|.
+  void ReportDataUseUMA(const net::URLRequest* request);

[sclittle, 2015/08/26 23:08:30]

Could you write some simple tests for this method in
data_use_measurement_unittest.cc? They could be as simple as just using a
histogram tester and calling ReportDataUseUMA in all the different situations.

You could also have an android specific test for the BACKGROUND, FOREGROUND
case, that just calls OnApplicationStateChange(state) then checks that
ReportDataUseUMA is reported appropriately for each state of BACKGROUND and
FOREGROUND.

[amohammadkhan, 2015/08/29 01:00:59]

I tried to have a complete test as much as possible. But the class providing
connection type didn't provide any facility to test in a way that can be used by
this code.

+
+#if defined(OS_ANDROID)
+  // If a change in application status happens, this function is called and this
+  // function sets app_state_ appropriately.
+  void OnApplicationStateChange(
+      base::android::ApplicationState application_state);
+#endif
+ private:
+  // Specifies that data is received or sent, respectively.
+  enum TrafficDirection { DOWNLOAD, UPLOAD };
+
+  // The state of the application. Only available on Android and on other
+  // platforms it is always FOREGROUND.
+  enum AppState { BACKGROUND, FOREGROUND };
+
+  // The type of network connection that was used.
+  enum ConnectionType { CELLULAR, NOT_CELLULAR };
+
+  // The reason a request was sent. Whether the traffic originates from
+  // user's request for a web site or a service is the source of the traffic.
+  enum ChromeTrafficType { USER_TRAFFIC, SERVICE_TRAFFIC };
+
+  // Returns the current application state (Foreground or Background). It always
+  // returns Foreground if Chrome is not running on Android.
+  AppState CurrentAppState();
+
+  // Returns the current connection type (Cellular or Not cellular).
+  ConnectionType CurrentConnectionType();
+
+  // The function produces a string representing the status of the Chrome when
+  // recording is done. Its output is in following form: dir.appState.ConnState
+  // for example: Upload.Foreground.Cellular is one of its possible outputs.
+  std::string DimensionMaker(TrafficDirection dir);
+
+  // Helper function used to record data use of services.
+  void ReportDataUsage(
+      data_use_measurement::DataUseUserData::ServiceType service,
+      TrafficDirection dir,
+      int64_t message_size);
+
+  // Helper function used for reporting data use of URLRequests.
+  void ReportDataUsageURLRequest(ChromeTrafficType service_type,
+                                 TrafficDirection dir,
+                                 int64_t message_size);
+
+#if defined(OS_ANDROID)
+  // Application listener store the last known state of the application in this
+  // field.
+  base::android::ApplicationState app_state_;
+
+  // ApplicationStatusListener used to monitor that application is in foreground
+  // or in background. It is owned by DataUseMeasurement
+  scoped_ptr<base::android::ApplicationStatusListener> app_listener_;
+#endif
+};
+}

[sclittle, 2015/08/26 23:08:30]

add a blank line above, and add a comment on the same line as the '}',

e.g. "}  // namespace data_use_measurement"

[amohammadkhan, 2015/08/29 01:00:59]

Done.

+#endif  // COMPONENTS_DATA_USE_MEASUREMENT_CONTENT_DATA_USE_MEASUREMENT_H_