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 ac24cd6912b3a713943af2960c79113cd1874e16..03ee35ce8499dd82533f59c743b3d51fc1e3a7b9 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 = data_usage::DataUseAggregator::Create();
+
   // 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(

[tbansal1, 2015/10/01 20:30:43]

May be move this after tracking_profile4 (right now it is between
tracking_profile3 and tracking_profile4)

[sclittle, 2015/10/03 03:27:52]

It's part of the setup for ChromeNetworkDelegate, so it looks like it has more
to do with tracking_profile3 ("InitAsync::ChromeNetworkDelegate") than
tracking_profile4 ("InitAsync::CreateGlobalHostResolver").

+      globals_->data_use_aggregator.get(),
+      true /* is_data_usage_off_the_record */);
 
   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
   // is fixed.