Implement UMA log throttling for cellular connections

chrome/browser/net/chrome_network_delegate.cc

 // Copyright (c) 2012 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 "chrome/browser/net/chrome_network_delegate.h"
 
 #include <stddef.h>
 #include <stdlib.h>
 
 #include <vector>
@@ skipping 268 matching lines @@
     if (CanRequestBeDeltaEncoded(request)) {
       UMA_HISTOGRAM_COUNTS("Net.CacheState.EncodeableBytes", size);
     }
   }
 }
 
 }  // namespace
 
 ChromeNetworkDelegate::ChromeNetworkDelegate(
     extensions::EventRouterForwarder* event_router,
-    BooleanPrefMember* enable_referrers)
+    BooleanPrefMember* enable_referrers,
+    metrics::UpdateUsagePrefCallbackType metrics_data_use_forwarder)
     : profile_(NULL),
       enable_referrers_(enable_referrers),
       enable_do_not_track_(NULL),
       force_google_safe_search_(NULL),
       force_youtube_safety_mode_(NULL),
       url_blacklist_manager_(NULL),
       domain_reliability_monitor_(NULL),
       experimental_web_platform_features_enabled_(
-          base::CommandLine::ForCurrentProcess()
-              ->HasSwitch(switches::kEnableExperimentalWebPlatformFeatures)),
+          base::CommandLine::ForCurrentProcess()->HasSwitch(
+              switches::kEnableExperimentalWebPlatformFeatures)),
       data_use_aggregator_(nullptr),
       is_data_usage_off_the_record_(true) {
   DCHECK(enable_referrers);
   extensions_delegate_.reset(
       ChromeExtensionsNetworkDelegate::Create(event_router));
+
+  // Pass callback for updating data use prefs to |DataUseMeasurement|  object.
+  data_use_measurement_.SetMetricsDataUseForwarder(metrics_data_use_forwarder);

[Alexei Svitkine (slow), 2016/03/31 04:32:25]

Can this be a ctor param for that object instead of having a setter?

[gayane -on leave until 09-2017, 2016/03/31 17:54:57]

Done.

 }
 
 ChromeNetworkDelegate::~ChromeNetworkDelegate() {}
 
 void ChromeNetworkDelegate::set_extension_info_map(
     extensions::InfoMap* extension_info_map) {
   extensions_delegate_->set_extension_info_map(extension_info_map);
 }
 
 void ChromeNetworkDelegate::set_profile(void* profile) {
@@ skipping 426 matching lines @@
   if (!data_use_aggregator_)
     return;
 
   if (is_data_usage_off_the_record_) {
     data_use_aggregator_->ReportOffTheRecordDataUse(tx_bytes, rx_bytes);
     return;
   }
 
   data_use_aggregator_->ReportDataUse(request, tx_bytes, rx_bytes);
 }