Added data reduction proxy holdback experiment

components/data_reduction_proxy/browser/data_reduction_proxy_settings.cc

 // Copyright 2014 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/data_reduction_proxy/browser/data_reduction_proxy_settings.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/metrics/field_trial.h"
 #include "base/metrics/histogram.h"
@@ skipping 109 matching lines @@
     net::URLRequestContextGetter* url_request_context_getter) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(prefs);
   DCHECK(local_state_prefs);
   DCHECK(url_request_context_getter);
   prefs_ = prefs;
   local_state_prefs_ = local_state_prefs;
   url_request_context_getter_ = url_request_context_getter;
   InitPrefMembers();
   RecordDataReductionInit();
-
   // Disable the proxy if it is not allowed to be used.
   if (!params_->allowed())
     return;
 
   AddDefaultProxyBypassRules();
   net::NetworkChangeNotifier::AddIPAddressObserver(this);
 
   // We set or reset the proxy pref at startup.
   MaybeActivateDataReductionProxy(true);
 }
@@ skipping 228 matching lines @@
     bool at_startup) {
   DCHECK(thread_checker_.CalledOnValidThread());
   PrefService* prefs = GetOriginalProfilePrefs();
   // TODO(marq): Consider moving this so stats are wiped the first time the
   // proxy settings are actually (not maybe) turned on.
   if (spdy_proxy_auth_enabled_.GetValue() &&
       !prefs->GetBoolean(prefs::kDataReductionProxyWasEnabledBefore)) {
     prefs->SetBoolean(prefs::kDataReductionProxyWasEnabledBefore, true);
     ResetDataReductionStatistics();
   }
-
   // Configure use of the data reduction proxy if it is enabled.
   enabled_by_user_= IsDataReductionProxyEnabled();
   SetProxyConfigs(enabled_by_user_ && !disabled_on_vpn_,
                   IsDataReductionProxyAlternativeEnabled(),
                   restricted_by_carrier_,
                   at_startup);
 
   // Check if the proxy has been restricted explicitly by the carrier.
   if (enabled_by_user_ && !disabled_on_vpn_) {
     ProbeWhetherDataReductionProxyIsAvailable();
     WarmProxyConnection();
   }
 }
 
 void DataReductionProxySettings::SetProxyConfigs(bool enabled,
                                                  bool alternative_enabled,
                                                  bool restricted,
                                                  bool at_startup) {
   DCHECK(thread_checker_.CalledOnValidThread());
   LogProxyState(enabled, restricted, at_startup);
   // The alternative is only configured if the standard configuration is
   // is enabled.
-  if (enabled) {
+  if (enabled & !params_->holdback()) {
     if (alternative_enabled) {
       configurator_->Enable(restricted,
                             !params_->fallback_allowed(),
                             params_->alt_origin().spec(),
                             params_->alt_fallback_origin().spec(),
                             params_->ssl_origin().spec());
     } else {
       configurator_->Enable(restricted,
                             !params_->fallback_allowed(),
                             params_->origin().spec(),
@@ skipping 169 matching lines @@
     SetProxyConfigs(enabled_by_user_,
                     IsDataReductionProxyAlternativeEnabled(),
                     restricted_by_carrier_,
                     false);
   }
   disabled_on_vpn_ = false;
   return false;
 }
 
 }  // namespace data_reduction_proxy