Complete the layered architecture of data_use_measurement component.

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 "content/public/browser/resource_request_info.h"
-#include "net/base/network_change_notifier.h"
-#include "net/base/upload_data_stream.h"
-#include "net/http/http_response_headers.h"
-#include "net/url_request/url_request.h"
-
-namespace data_use_measurement {
-
-namespace {
-
-// Records the occurrence of |sample| in |name| histogram. Conventional UMA
-// histograms are not used because the |name| is not static.
-void RecordUMAHistogramCount(const std::string& name, int64_t sample) {
-  base::HistogramBase* histogram_pointer = base::Histogram::FactoryGet(
-      name,
-      1,        // Minimum sample size in bytes.
-      1000000,  // Maximum sample size in bytes. Should cover most of the
-                // requests by services.
-      50,       // Bucket count.
-      base::HistogramBase::kUmaTargetedHistogramFlag);
-  histogram_pointer->Add(sample);
-}
-
-// This function increases the value of |sample| bucket in |name| sparse
-// histogram by |value|. Conventional UMA histograms are not used because |name|
-// is not static.
-void IncreaseSparseHistogramByValue(const std::string& name,
-                                    int64_t sample,
-                                    int64_t value) {
-  base::HistogramBase* histogram = base::SparseHistogram::FactoryGet(
-      name, base::HistogramBase::kUmaTargetedHistogramFlag);
-  histogram->AddCount(sample, value);
-}
-
-}  // namespace
-
-DataUseMeasurement::DataUseMeasurement()
-#if defined(OS_ANDROID)
-    : app_state_(base::android::APPLICATION_STATE_HAS_RUNNING_ACTIVITIES),
-      app_listener_(new base::android::ApplicationStatusListener(
-          base::Bind(&DataUseMeasurement::OnApplicationStateChange,
-                     base::Unretained(this))))
-#endif
-{
-}
-
-DataUseMeasurement::~DataUseMeasurement(){};
-
-void DataUseMeasurement::ReportDataUseUMA(
-    const net::URLRequest* request) const {
-  const content::ResourceRequestInfo* info =
-      content::ResourceRequestInfo::ForRequest(request);
-  // Having |info| is the sign of a request for a web content from user. For now
-  // we could add a condition to check ProcessType in info is
-  // content::PROCESS_TYPE_RENDERER, but it won't be compatible with upcoming
-  // PlzNavigate architecture. So just existence of |info| is verified, and the
-  // current check should be compatible with upcoming changes in PlzNavigate.
-  bool is_user_traffic = info != nullptr;
-
-  // Counts rely on URLRequest::GetTotalReceivedBytes() and
-  // URLRequest::GetTotalSentBytes(), which does not include the send path,
-  // network layer overhead, TLS overhead, and DNS.
-  // TODO(amohammadkhan): Make these measured bytes more in line with number of
-  // bytes in lower levels.
-  int64_t total_upload_bytes = request->GetTotalSentBytes();
-  int64_t total_received_bytes = request->GetTotalReceivedBytes();
-
-  RecordUMAHistogramCount(
-      GetHistogramName(is_user_traffic ? "DataUse.TrafficSize.User"
-                                       : "DataUse.TrafficSize.System",
-                       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));
-
-  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);
-  }
-}
-
-#if defined(OS_ANDROID)
-void DataUseMeasurement::OnApplicationStateChangeForTesting(
-    base::android::ApplicationState application_state) {
-  app_state_ = application_state;
-}
-#endif
-
-DataUseMeasurement::AppState DataUseMeasurement::CurrentAppState() const {
-#if defined(OS_ANDROID)
-  if (app_state_ != base::android::APPLICATION_STATE_HAS_RUNNING_ACTIVITIES)
-    return BACKGROUND;
-#endif
-  // If the OS is not Android, all the requests are considered Foreground.
-  return FOREGROUND;
-}
-
-std::string DataUseMeasurement::GetHistogramName(const char* prefix,
-                                                 TrafficDirection dir) const {
-  AppState app_state = CurrentAppState();
-  bool is_conn_cellular = net::NetworkChangeNotifier::IsConnectionCellular(
-      net::NetworkChangeNotifier::GetConnectionType());
-  return base::StringPrintf(
-      "%s.%s.%s.%s", prefix, dir == UPSTREAM ? "Upstream" : "Downstream",
-      app_state == BACKGROUND ? "Background" : "Foreground",
-      is_conn_cellular ? "Cellular" : "NotCellular");
-}
-
-#if defined(OS_ANDROID)
-void DataUseMeasurement::OnApplicationStateChange(
-    base::android::ApplicationState application_state) {
-  app_state_ = application_state;
-}
-#endif
-
-void DataUseMeasurement::ReportDataUsageServices(
-    DataUseUserData::ServiceName service,
-    TrafficDirection dir,
-    int64_t message_size) const {
-  RecordUMAHistogramCount(
-      "DataUse.MessageSize." + DataUseUserData::GetServiceNameAsString(service),
-      message_size);
-  if (message_size > 0) {
-    IncreaseSparseHistogramByValue(
-        GetHistogramName("DataUse.MessageSize.AllServices", dir), service,
-        message_size);
-  }
-}
-
-}  // namespace data_use_measurement