Cleanup the preconnect to proxy code and Job controller code

components/network_session_configurator/network_session_configurator.cc

 // Copyright 2016 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 "components/network_session_configurator/network_session_configurator.h"
 
 #include <map>
 
 #include "base/metrics/field_trial.h"
 #include "base/strings/string_number_conversions.h"
@@ skipping 350 matching lines @@
   params->quic_user_agent_id = quic_user_agent_id;
 
   net::QuicVersion version = GetQuicVersion(quic_trial_params);
   if (version != net::QUIC_VERSION_UNSUPPORTED) {
     net::QuicVersionVector supported_versions;
     supported_versions.push_back(version);
     params->quic_supported_versions = supported_versions;
   }
 }
 
+void ConfigureOptimizePreconnectsToProxiesParams(
+    const std::map<std::string, std::string>& proxy_preconnects_trial_params,
+    net::HttpNetworkSession::Params* params) {
+  params->restrict_to_one_preconnect_for_proxies =
+      GetVariationParam(proxy_preconnects_trial_params,
+                        "restrict_to_one_preconnect_for_proxies") == "true";
+}
+
 }  // anonymous namespace
 
 namespace network_session_configurator {
 
 net::QuicVersion ParseQuicVersion(const std::string& quic_version) {
   net::QuicVersionVector supported_versions = net::AllSupportedVersions();
   for (size_t i = 0; i < supported_versions.size(); ++i) {
     net::QuicVersion version = supported_versions[i];
     if (net::QuicVersionToString(version) == quic_version) {
       return version;
@@ skipping 16 matching lines @@
                       is_quic_force_disabled, is_quic_force_enabled,
                       quic_user_agent_id, params);
 
   std::string http2_trial_group =
       base::FieldTrialList::FindFullName(kHttp2FieldTrialName);
   ConfigureHttp2Params(http2_trial_group, params);
 
   const std::string tfo_trial_group =
       base::FieldTrialList::FindFullName(kTCPFastOpenFieldTrialName);
   ConfigureTCPFastOpenParams(tfo_trial_group, params);
+
+  std::map<std::string, std::string> proxy_preconnects_trial_params;
+  variations::GetVariationParams("NetProxyPreconnects",
+                                 &proxy_preconnects_trial_params);
+  ConfigureOptimizePreconnectsToProxiesParams(proxy_preconnects_trial_params,
+                                              params);
 }
 
 }  // namespace network_session_configurator