Propagate network delegate events to ChromeDataUseAscriber.

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 f7cf37e78d4bb088eaee3eba1c4df6860c8170cc..c7556bfe993d8df45e522818af7251a6eba92259 100644
--- a/chrome/browser/io_thread.cc
+++ b/chrome/browser/io_thread.cc
@@ -49,6 +49,8 @@
 #include "components/data_usage/core/data_use_aggregator.h"
 #include "components/data_usage/core/data_use_amortizer.h"
 #include "components/data_usage/core/data_use_annotator.h"
+#include "components/data_use_measurement/core/data_use_ascriber.h"

[mmenke, 2016/09/22 14:36:45]

Not needed, since you never derefernce one of these, see other comment, though. 
Both comments apply to both files.

[Not at Google. Contact bengr, 2016/09/22 16:35:56]

Done.

+#include "components/data_use_measurement/core/data_use_network_delegate.h"
 #include "components/metrics/metrics_service.h"
 #include "components/net_log/chrome_net_log.h"
 #include "components/network_session_configurator/network_session_configurator.h"
@@ -528,7 +530,11 @@ void IOThread::Init() {
           BrowserThread::GetTaskRunnerForThread(BrowserThread::UI)));
 #endif
 
-  globals_->system_network_delegate = std::move(chrome_network_delegate);
+  globals_->system_network_delegate =
+      base::MakeUnique<data_use_measurement::DataUseNetworkDelegate>(
+          std::move(chrome_network_delegate),
+          globals_->data_use_ascriber.get());

[mmenke, 2016/09/22 14:36:45]

optional:  I'd suggest making this method:

globals_->data_use_ascriber->CreateNetworkDelegate(
    std::move(chrome_network_delegate));

Instead.  Then we only have to know about one DataUse class, and the ascriber
will (hopefully) be responsible for any changes in the API.  I only have a weak
preference for this, so if you prefer this approach, that's fine.

[Not at Google. Contact bengr, 2016/09/22 16:35:56]

Done. I like this suggestion since it makes the interface of the
data_use_measurement component cleaner as well.

+
   globals_->host_resolver = CreateGlobalHostResolver(net_log_);
 
   std::map<std::string, std::string> network_quality_estimator_params;