Add network quality change events to net log

ios/chrome/browser/ios_chrome_io_thread.mm

 // 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 "ios/chrome/browser/ios_chrome_io_thread.h"
 
 #include <stddef.h>
 
 #include <utility>
 #include <vector>
@@ skipping 342 matching lines @@
   globals_->system_network_delegate = std::move(chrome_network_delegate);
   globals_->host_resolver = CreateGlobalHostResolver(net_log_);
 
   std::map<std::string, std::string> network_quality_estimator_params;
   variations::GetVariationParams(kNetworkQualityEstimatorFieldTrialName,
                                  &network_quality_estimator_params);
 
   std::unique_ptr<net::ExternalEstimateProvider> external_estimate_provider;
   // Pass ownership.
   globals_->network_quality_estimator.reset(new net::NetworkQualityEstimator(
-      std::move(external_estimate_provider), network_quality_estimator_params));
+      std::move(external_estimate_provider), network_quality_estimator_params,
+      net_log_));
 
   globals_->cert_verifier = net::CertVerifier::CreateDefault();
 
   globals_->transport_security_state.reset(new net::TransportSecurityState());
 
   std::vector<scoped_refptr<const net::CTLogVerifier>> ct_logs(
       net::ct::CreateLogVerifiersForKnownLogs());
 
   net::MultiLogCTVerifier* ct_verifier = new net::MultiLogCTVerifier();
   globals_->cert_transparency_verifier.reset(ct_verifier);
@@ skipping 193 matching lines @@
 
   globals->system_http_network_session.reset(
       new net::HttpNetworkSession(system_params));
   globals->system_http_transaction_factory.reset(
       new net::HttpNetworkLayer(globals->system_http_network_session.get()));
   context->set_http_transaction_factory(
       globals->system_http_transaction_factory.get());
 
   return context;
 }