Create component to expose network usage stats to consumers.

chrome/browser/io_thread.cc

Index: chrome/browser/io_thread.cc
diff --git a/chrome/browser/io_thread.cc b/chrome/browser/io_thread.cc
index bfa56f23efcc2eb040046653bdf6e70c6bfe89c3..165bf37aaafac32b370109297fbcd70c6021dfa4 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -40,6 +40,7 @@
 #include "chrome/common/pref_names.h"
 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_prefs.h"
 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
+#include "components/data_usage/core/data_use_aggregator.h"
 #include "components/net_log/chrome_net_log.h"
 #include "components/policy/core/common/policy_service.h"
 #include "components/proxy_config/pref_proxy_config_tracker.h"
@@ -567,6 +568,8 @@ void IOThread::Init() {
       extension_event_router_forwarder_;
 #endif
 
+  globals_->data_use_aggregator.reset(new data_usage::DataUseAggregator());
+
   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
   // is fixed.
   tracked_objects::ScopedTracker tracking_profile3(
@@ -575,6 +578,10 @@ void IOThread::Init() {
   scoped_ptr<ChromeNetworkDelegate> chrome_network_delegate(
       new ChromeNetworkDelegate(extension_event_router_forwarder(),
                                 &system_enable_referrers_));
+  // By default, data usage is considered off the record.
+  chrome_network_delegate->set_data_use_aggregator(
+      globals_->data_use_aggregator.get(),
+      true /* is_data_usage_off_the_record */);
 
   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
   // is fixed.