Added alternative configuration for the data reduction proxy

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"
 #include "base/prefs/pref_member.h"
 #include "base/prefs/pref_service.h"
 #include "base/prefs/scoped_user_pref_update.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/data_reduction_proxy/browser/data_reduction_proxy_configurator.h"
+#include "components/data_reduction_proxy/browser/data_reduction_proxy_params.h"
 #include "components/data_reduction_proxy/common/data_reduction_proxy_pref_names.h"
 #include "components/data_reduction_proxy/common/data_reduction_proxy_switches.h"
 #include "crypto/random.h"
 #include "net/base/auth.h"
 #include "net/base/host_port_pair.h"
 #include "net/base/load_flags.h"
 #include "net/base/net_errors.h"
 #include "net/http/http_auth.h"
 #include "net/http/http_auth_cache.h"
 #include "net/http/http_network_session.h"
 #include "net/http/http_response_headers.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_fetcher_delegate.h"
 #include "net/url_request/url_request_context_getter.h"
 #include "net/url_request/url_request_status.h"
 #include "url/gurl.h"
 
-using base::FieldTrialList;
+
 using base::StringPrintf;
 
 namespace {
 
 // Key of the UMA DataReductionProxy.StartupState histogram.
 const char kUMAProxyStartupStateHistogram[] =
     "DataReductionProxy.StartupState";
 
 // Key of the UMA DataReductionProxy.ProbeURL histogram.
 const char kUMAProxyProbeURL[] = "DataReductionProxy.ProbeURL";
 
-const char kEnabled[] = "Enabled";
-
 // TODO(marq): Factor this string out into a constant here and in
 //             http_auth_handler_spdyproxy.
 const char kAuthenticationRealmName[] = "SpdyProxy";
 
 int64 GetInt64PrefValue(const base::ListValue& list_value, size_t index) {
   int64 val = 0;
   std::string pref_value;
   bool rv = list_value.GetString(index, &pref_value);
   DCHECK(rv);
   if (rv) {
     rv = base::StringToInt64(pref_value, &val);
     DCHECK(rv);
   }
   return val;
 }
 
 }  // namespace
 
 namespace data_reduction_proxy {
 
-bool DataReductionProxySettings::allowed_;
-bool DataReductionProxySettings::promo_allowed_;
-
-// static
-bool DataReductionProxySettings::IsProxyOriginSetOnCommandLine() {
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  return command_line.HasSwitch(
-      data_reduction_proxy::switches::kDataReductionProxy);
-}
-
-// static
-bool DataReductionProxySettings::IsProxyKeySetOnCommandLine() {
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  return command_line.HasSwitch(
-      data_reduction_proxy::switches::kEnableDataReductionProxy);
-}
-
-// static
-bool DataReductionProxySettings::IsIncludedInFieldTrialOrFlags() {
-  return (base::FieldTrialList::FindFullName(
-              "DataCompressionProxyRollout") == kEnabled ||
-          IsProxyOriginSetOnCommandLine());
-}
-
-// static
-void DataReductionProxySettings::SetAllowed(bool allowed) {
-  allowed_ = allowed;
-}
-
-// static
-void DataReductionProxySettings::SetPromoAllowed(bool promo_allowed) {
-  promo_allowed_ = promo_allowed;
-}
-
-DataReductionProxySettings::DataReductionProxySettings()
+DataReductionProxySettings::DataReductionProxySettings(
+    DataReductionProxyParams* params)
     : restricted_by_carrier_(false),
       enabled_by_user_(false),
       prefs_(NULL),
       local_state_prefs_(NULL),
-      url_request_context_getter_(NULL),
-      fallback_allowed_(true) {
+      url_request_context_getter_(NULL) {
+  DCHECK(params);
+  params_.reset(params);
 }
 
 DataReductionProxySettings::~DataReductionProxySettings() {
-  if (IsDataReductionProxyAllowed())
+  if (params_->allowed())
     spdy_proxy_auth_enabled_.Destroy();
 }
 
 void DataReductionProxySettings::InitPrefMembers() {
   DCHECK(thread_checker_.CalledOnValidThread());
   spdy_proxy_auth_enabled_.Init(
       prefs::kDataReductionProxyEnabled,
       GetOriginalProfilePrefs(),
       base::Bind(&DataReductionProxySettings::OnProxyEnabledPrefChange,
                  base::Unretained(this)));
+  data_reduction_proxy_alternative_enabled_.Init(
+      prefs::kDataReductionProxyAltEnabled,
+      GetOriginalProfilePrefs(),
+      base::Bind(
+          &DataReductionProxySettings::OnProxyAlternativeEnabledPrefChange,
+          base::Unretained(this)));
 }
 
 void DataReductionProxySettings::InitDataReductionProxySettings(
     PrefService* prefs,
     PrefService* local_state_prefs,
     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 (!IsDataReductionProxyAllowed())
+  if (!params_->allowed())
     return;
 
   AddDefaultProxyBypassRules();
   net::NetworkChangeNotifier::AddIPAddressObserver(this);
 
   // We set or reset the proxy pref at startup.
   MaybeActivateDataReductionProxy(true);
 }
 
 void DataReductionProxySettings::InitDataReductionProxySettings(
     PrefService* prefs,
     PrefService* local_state_prefs,
     net::URLRequestContextGetter* url_request_context_getter,
-    scoped_ptr<DataReductionProxyConfigurator> config) {
+    scoped_ptr<DataReductionProxyConfigurator> configurator) {
   InitDataReductionProxySettings(prefs,
                                  local_state_prefs,
                                  url_request_context_getter);
-  SetProxyConfigurator(config.Pass());
+  SetProxyConfigurator(configurator.Pass());
 }
 
 void DataReductionProxySettings::SetProxyConfigurator(
     scoped_ptr<DataReductionProxyConfigurator> configurator) {
   DCHECK(configurator);
-  config_ = configurator.Pass();
+  configurator_ = configurator.Pass();
 }
 
 // static
 void DataReductionProxySettings::InitDataReductionProxySession(
     net::HttpNetworkSession* session,
-    const std::string& key) {
-  // This is a no-op unless the key is set. (even though values for them may be
-  // specified on the command line). Authentication will still work if the
-  // command line parameters are used, however there will be a round-trip
-  // overhead for each challenge/response (typically once per session).
-  // TODO(bengr):Pass a configuration struct into
-  // DataReductionProxyConfigurator's constructor.
-  if (key.empty())
-    return;
+    const DataReductionProxyParams* params) {
+// This is a no-op unless the authentication parameters are compiled in.
+// (even though values for them may be specified on the command line).
+// Authentication will still work if the command line parameters are used,
+// however there will be a round-trip overhead for each challenge/response
+// (typically once per session).
+// TODO(bengr):Pass a configuration struct into DataReductionProxyConfigurator's
+// constructor. The struct would carry everything in the preprocessor flags.
   DCHECK(session);
   net::HttpAuthCache* auth_cache = session->http_auth_cache();
   DCHECK(auth_cache);
-  InitDataReductionAuthentication(auth_cache, key);
+  InitDataReductionAuthentication(auth_cache, params);
 }
 
 // static
 void DataReductionProxySettings::InitDataReductionAuthentication(
     net::HttpAuthCache* auth_cache,
-    const std::string& key) {
+    const DataReductionProxyParams* params) {
   DCHECK(auth_cache);
+  DCHECK(params);
   int64 timestamp =
       (base::Time::Now() - base::Time::UnixEpoch()).InMilliseconds() / 1000;
 
-  DataReductionProxyList proxies = GetDataReductionProxies();
-  for (DataReductionProxyList::iterator it = proxies.begin();
-      it != proxies.end(); ++it) {
+  DataReductionProxyParams::DataReductionProxyList proxies =
+      params->GetAllowedProxies();
+  for (DataReductionProxyParams::DataReductionProxyList::iterator it =
+           proxies.begin();
+       it != proxies.end(); ++it) {
     GURL auth_origin = (*it).GetOrigin();
+
     int32 rand[3];
     crypto::RandBytes(rand, 3 * sizeof(rand[0]));
 
     std::string realm =
         base::StringPrintf("%s%lld", kAuthenticationRealmName,
                            static_cast<long long>(timestamp));
     std::string challenge = base::StringPrintf(
         "%s realm=\"%s\", ps=\"%lld-%u-%u-%u\"",
         kAuthenticationRealmName,
         realm.data(),
         static_cast<long long>(timestamp),
         rand[0],
         rand[1],
         rand[2]);
-    base::string16 password = AuthHashForSalt(timestamp, key);
+    base::string16 password = AuthHashForSalt(timestamp, params->key());
 
     DVLOG(1) << "origin: [" << auth_origin << "] realm: [" << realm
         << "] challenge: [" << challenge << "] password: [" << password << "]";
 
     net::AuthCredentials credentials(base::string16(), password);
     // |HttpAuthController| searches this cache by origin and path, the latter
     // being '/' in the case of the data reduction proxy.
     auth_cache->Add(auth_origin,
                     realm,
                     net::HttpAuth::AUTH_SCHEME_SPDYPROXY,
                     challenge,
                     credentials,
                     std::string("/"));
   }
 }
 
-// TODO(bengr): Use a configuration struct to carry field trial state as well.
-// static
-bool DataReductionProxySettings::IsDataReductionProxyAllowed() {
-  return allowed_;
-}
-
-// static
-bool DataReductionProxySettings::IsDataReductionProxyPromoAllowed() {
-  return IsProxyOriginSetOnCommandLine() ||
-      (IsDataReductionProxyAllowed() && promo_allowed_);
-}
-
-// static
-bool DataReductionProxySettings::IsPreconnectHintingAllowed() {
-  if (!IsDataReductionProxyAllowed())
-    return false;
-  return FieldTrialList::FindFullName("DataCompressionProxyPreconnectHints") ==
-      kEnabled;
-}
-
-// static
-std::string DataReductionProxySettings::GetDataReductionProxyOrigin() {
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  if (command_line.HasSwitch(switches::kDataReductionProxyDev))
-    return command_line.GetSwitchValueASCII(switches::kDataReductionProxyDev);
-  if (command_line.HasSwitch(switches::kDataReductionProxy))
-    return command_line.GetSwitchValueASCII(switches::kDataReductionProxy);
-#if defined(DATA_REDUCTION_DEV_HOST)
-  if (FieldTrialList::FindFullName("DataCompressionProxyDevRollout") ==
-      kEnabled) {
-    return DATA_REDUCTION_DEV_HOST;
-  }
-#endif
-#if defined(SPDY_PROXY_AUTH_ORIGIN)
-  return SPDY_PROXY_AUTH_ORIGIN;
-#else
-  return std::string();
-#endif
-}
-
-// static
-std::string DataReductionProxySettings::GetDataReductionProxyFallback() {
-  // Regardless of what else is defined, only return a value if the main proxy
-  // origin is defined.
-  if (GetDataReductionProxyOrigin().empty())
-    return std::string();
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  if (command_line.HasSwitch(switches::kDataReductionProxyFallback)) {
-    return command_line.GetSwitchValueASCII(
-        switches::kDataReductionProxyFallback);
-  }
-#if defined(DATA_REDUCTION_FALLBACK_HOST)
-  return DATA_REDUCTION_FALLBACK_HOST;
-#else
-  return std::string();
-#endif
-}
-
-// static
 bool DataReductionProxySettings::IsAcceptableAuthChallenge(
     net::AuthChallengeInfo* auth_info) {
   // Challenge realm must start with the authentication realm name.
   std::string realm_prefix =
       auth_info->realm.substr(0, strlen(kAuthenticationRealmName));
   if (realm_prefix != kAuthenticationRealmName)
     return false;
 
   // The challenger must be one of the configured proxies.
-  DataReductionProxyList proxies = GetDataReductionProxies();
-  for (DataReductionProxyList::iterator it = proxies.begin();
+  DataReductionProxyParams::DataReductionProxyList proxies =
+      params_->GetAllowedProxies();
+  for (DataReductionProxyParams::DataReductionProxyList::iterator it =
+       proxies.begin();
        it != proxies.end(); ++it) {
     net::HostPortPair origin_host = net::HostPortPair::FromURL(*it);
     if (origin_host.Equals(auth_info->challenger))
       return true;
   }
   return false;
 }
 
 base::string16 DataReductionProxySettings::GetTokenForAuthChallenge(
     net::AuthChallengeInfo* auth_info) {
   if (auth_info->realm.length() > strlen(kAuthenticationRealmName)) {
     int64 salt;
     std::string realm_suffix =
         auth_info->realm.substr(strlen(kAuthenticationRealmName));
     if (base::StringToInt64(realm_suffix, &salt)) {
-      return AuthHashForSalt(salt, key_);
+      return AuthHashForSalt(salt, params_->key());
     } else {
       DVLOG(1) << "Unable to parse realm name " << auth_info->realm
                << "into an int for salting.";
       return base::string16();
     }
   } else {
     return base::string16();
   }
 }
 
 bool DataReductionProxySettings::IsDataReductionProxyEnabled() {
   return spdy_proxy_auth_enabled_.GetValue() ||
-      IsProxyKeySetOnCommandLine();
+      DataReductionProxyParams::IsKeySetOnCommandLine();
+}
+
+bool DataReductionProxySettings::IsDataReductionProxyAlternativeEnabled() {
+  return data_reduction_proxy_alternative_enabled_.GetValue();
 }
 
 bool DataReductionProxySettings::IsDataReductionProxyManaged() {
   return spdy_proxy_auth_enabled_.IsManaged();
 }
 
-// static
-DataReductionProxySettings::DataReductionProxyList
-DataReductionProxySettings::GetDataReductionProxies() {
-  DataReductionProxyList proxies;
-  std::string proxy = GetDataReductionProxyOrigin();
-  std::string fallback = GetDataReductionProxyFallback();
-
-  if (!proxy.empty())
-    proxies.push_back(GURL(proxy));
-
-  if (!fallback.empty()) {
-    // Sanity check: fallback isn't the only proxy.
-    DCHECK(!proxies.empty());
-    proxies.push_back(GURL(fallback));
-  }
-
-  return proxies;
-}
-
 void DataReductionProxySettings::SetDataReductionProxyEnabled(bool enabled) {
   DCHECK(thread_checker_.CalledOnValidThread());
   // Prevent configuring the proxy when it is not allowed to be used.
-  if (!IsDataReductionProxyAllowed())
+  if (!params_->allowed())
     return;
 
   if (spdy_proxy_auth_enabled_.GetValue() != enabled) {
     spdy_proxy_auth_enabled_.SetValue(enabled);
     OnProxyEnabledPrefChange();
   }
 }
 
+void DataReductionProxySettings::SetDataReductionProxyAlternativeEnabled(
+    bool enabled) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  // Prevent configuring the proxy when it is not allowed to be used.
+  if (!params_->alternative_allowed())
+    return;
+  if (data_reduction_proxy_alternative_enabled_.GetValue() != enabled) {
+    data_reduction_proxy_alternative_enabled_.SetValue(enabled);
+    OnProxyAlternativeEnabledPrefChange();
+  }
+}
+
 int64 DataReductionProxySettings::GetDataReductionLastUpdateTime() {
   DCHECK(thread_checker_.CalledOnValidThread());
   PrefService* local_state = GetLocalStatePrefs();
   int64 last_update_internal =
       local_state->GetInt64(prefs::kDailyHttpContentLengthLastUpdateDate);
   base::Time last_update = base::Time::FromInternalValue(last_update_internal);
   return static_cast<int64>(last_update.ToJsTime());
 }
 
 DataReductionProxySettings::ContentLengthList
@@ skipping 24 matching lines @@
   if ("OK" == response.substr(0, 2)) {
     DVLOG(1) << "The data reduction proxy is unrestricted.";
 
     if (enabled_by_user_) {
       if (restricted_by_carrier_) {
         // The user enabled the proxy, but sometime previously in the session,
         // the network operator had blocked the canary and restricted the user.
         // The current network doesn't block the canary, so don't restrict the
         // proxy configurations.
         SetProxyConfigs(true /* enabled */,
+                        IsDataReductionProxyAlternativeEnabled(),
                         false /* restricted */,
                         false /* at_startup */);
         RecordProbeURLFetchResult(SUCCEEDED_PROXY_ENABLED);
       } else {
         RecordProbeURLFetchResult(SUCCEEDED_PROXY_ALREADY_ENABLED);
       }
     }
     restricted_by_carrier_ = false;
     return;
   }
   DVLOG(1) << "The data reduction proxy is restricted to the configured "
            << "fallback proxy.";
   if (enabled_by_user_) {
     if (!restricted_by_carrier_) {
       // Restrict the proxy.
       SetProxyConfigs(true /* enabled */,
+                      IsDataReductionProxyAlternativeEnabled(),
                       true /* restricted */,
                       false /* at_startup */);
       RecordProbeURLFetchResult(FAILED_PROXY_DISABLED);
     } else {
       RecordProbeURLFetchResult(FAILED_PROXY_ALREADY_DISABLED);
     }
   }
   restricted_by_carrier_ = true;
 }
 
-void DataReductionProxySettings::OnIPAddressChanged() {
+PrefService* DataReductionProxySettings::GetOriginalProfilePrefs() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  if (enabled_by_user_) {
-    DCHECK(IsDataReductionProxyAllowed());
-    ProbeWhetherDataReductionProxyIsAvailable();
-  }
+  return prefs_;
 }
 
-void DataReductionProxySettings::OnProxyEnabledPrefChange() {
+PrefService* DataReductionProxySettings::GetLocalStatePrefs() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  if (!DataReductionProxySettings::IsDataReductionProxyAllowed())
-    return;
-  MaybeActivateDataReductionProxy(false);
+  return local_state_prefs_;
 }
 
 void DataReductionProxySettings::AddDefaultProxyBypassRules() {
   // localhost
-  config_->AddHostPatternToBypass("<local>");
+  configurator_->AddHostPatternToBypass("<local>");
   // RFC1918 private addresses.
-  config_->AddHostPatternToBypass("10.0.0.0/8");
-  config_->AddHostPatternToBypass("172.16.0.0/12");
-  config_->AddHostPatternToBypass("192.168.0.0/16");
+  configurator_->AddHostPatternToBypass("10.0.0.0/8");
+  configurator_->AddHostPatternToBypass("172.16.0.0/12");
+  configurator_->AddHostPatternToBypass("192.168.0.0/16");
   // RFC4193 private addresses.
-  config_->AddHostPatternToBypass("fc00::/7");
+  configurator_->AddHostPatternToBypass("fc00::/7");
   // IPV6 probe addresses.
-  config_->AddHostPatternToBypass("*-ds.metric.gstatic.com");
-  config_->AddHostPatternToBypass("*-v4.metric.gstatic.com");
+  configurator_->AddHostPatternToBypass("*-ds.metric.gstatic.com");
+  configurator_->AddHostPatternToBypass("*-v4.metric.gstatic.com");
 }
 
 void DataReductionProxySettings::LogProxyState(
     bool enabled, bool restricted, bool at_startup) {
   // This must stay a LOG(WARNING); the output is used in processing customer
   // feedback.
   const char kAtStartup[] = "at startup";
   const char kByUser[] = "by user action";
   const char kOn[] = "ON";
   const char kOff[] = "OFF";
   const char kRestricted[] = "(Restricted)";
   const char kUnrestricted[] = "(Unrestricted)";
 
   std::string annotated_on =
       kOn + std::string(" ") + (restricted ? kRestricted : kUnrestricted);
 
   LOG(WARNING) << "SPDY proxy " << (enabled ? annotated_on : kOff)
                << " " << (at_startup ? kAtStartup : kByUser);
 }
 
-PrefService* DataReductionProxySettings::GetOriginalProfilePrefs() {
+void DataReductionProxySettings::OnIPAddressChanged() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  return prefs_;
+  if (enabled_by_user_) {
+    DCHECK(params_->allowed());
+    ProbeWhetherDataReductionProxyIsAvailable();
+  }
 }
 
-PrefService* DataReductionProxySettings::GetLocalStatePrefs() {
+void DataReductionProxySettings::OnProxyEnabledPrefChange() {
   DCHECK(thread_checker_.CalledOnValidThread());
-  return local_state_prefs_;
+  if (!params_->allowed())
+    return;
+  MaybeActivateDataReductionProxy(false);
+}
+
+void DataReductionProxySettings::OnProxyAlternativeEnabledPrefChange() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  if (!params_->alternative_allowed())
+    return;
+  MaybeActivateDataReductionProxy(false);
 }
 
 void DataReductionProxySettings::ResetDataReductionStatistics() {
   DCHECK(thread_checker_.CalledOnValidThread());
   PrefService* prefs = GetLocalStatePrefs();
   if (!prefs)
     return;
   ListPrefUpdate original_update(prefs, prefs::kDailyHttpOriginalContentLength);
   ListPrefUpdate received_update(prefs, prefs::kDailyHttpReceivedContentLength);
   original_update->Clear();
   received_update->Clear();
   for (size_t i = 0; i < kNumDaysInHistory; ++i) {
     original_update->AppendString(base::Int64ToString(0));
     received_update->AppendString(base::Int64ToString(0));
   }
 }
 
 void DataReductionProxySettings::MaybeActivateDataReductionProxy(
     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();
   }
 
-  std::string proxy = GetDataReductionProxyOrigin();
-  // Configure use of the data reduction proxy if it is enabled and the proxy
-  // origin is non-empty.
-  enabled_by_user_= IsDataReductionProxyEnabled() && !proxy.empty();
-  SetProxyConfigs(enabled_by_user_, restricted_by_carrier_, at_startup);
+  // Configure use of the data reduction proxy if it is enabled.
+  enabled_by_user_= IsDataReductionProxyEnabled();
+  SetProxyConfigs(enabled_by_user_,
+                  IsDataReductionProxyAlternativeEnabled(),
+                  restricted_by_carrier_,
+                  at_startup);
 
   // Check if the proxy has been restricted explicitly by the carrier.
   if (enabled_by_user_)
     ProbeWhetherDataReductionProxyIsAvailable();
 }
 
-void DataReductionProxySettings::SetProxyConfigs(
-    bool enabled, bool restricted, bool at_startup) {
+void DataReductionProxySettings::SetProxyConfigs(bool enabled,
+                                                 bool alternative_enabled,
+                                                 bool restricted,
+                                                 bool at_startup) {
   DCHECK(thread_checker_.CalledOnValidThread());
-  // If |restricted| is true and there is no defined fallback proxy.
-  // treat this as a disable.
-  std::string fallback = GetDataReductionProxyFallback();
-  if (fallback.empty() && enabled && restricted)
-      enabled = false;
-
   LogProxyState(enabled, restricted, at_startup);
+  // The alternative is only configured if the standard configuration is
+  // is enabled.
   if (enabled) {
-    config_->Enable(restricted,
-                    !fallback_allowed_,
-                    GetDataReductionProxyOrigin(),
-                    fallback);
+    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(),
+                            params_->fallback_origin().spec(),
+                            std::string());
+    }
   } else {
-    config_->Disable();
+    configurator_->Disable();
   }
 }
 
 // Metrics methods
 void DataReductionProxySettings::RecordDataReductionInit() {
   DCHECK(thread_checker_.CalledOnValidThread());
   ProxyStartupState state = PROXY_NOT_AVAILABLE;
-  if (IsDataReductionProxyAllowed()) {
+  if (params_->allowed()) {
     if (IsDataReductionProxyEnabled())
       state = PROXY_ENABLED;
     else
       state = PROXY_DISABLED;
   }
 
   RecordStartupState(state);
 }
 
 void DataReductionProxySettings::RecordProbeURLFetchResult(
     ProbeURLFetchResult result) {
   UMA_HISTOGRAM_ENUMERATION(kUMAProxyProbeURL,
                             result,
                             PROBE_URL_FETCH_RESULT_COUNT);
 }
 
 void DataReductionProxySettings::RecordStartupState(ProxyStartupState state) {
   UMA_HISTOGRAM_ENUMERATION(kUMAProxyStartupStateHistogram,
                             state,
                             PROXY_STARTUP_STATE_COUNT);
 }
 
+void DataReductionProxySettings::ResetParamsForTest(
+    DataReductionProxyParams* params) {
+  params_.reset(params);
+}
+
 DataReductionProxySettings::ContentLengthList
 DataReductionProxySettings::GetDailyContentLengths(const char* pref_name) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DataReductionProxySettings::ContentLengthList content_lengths;
   const base::ListValue* list_value = GetLocalStatePrefs()->GetList(pref_name);
   if (list_value->GetSize() == kNumDaysInHistory) {
     for (size_t i = 0; i < kNumDaysInHistory; ++i) {
       content_lengths.push_back(GetInt64PrefValue(*list_value, i));
     }
   }
   return content_lengths;
- }
+}
 
 void DataReductionProxySettings::GetContentLengths(
     unsigned int days,
     int64* original_content_length,
     int64* received_content_length,
     int64* last_update_time) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK_LE(days, kNumDaysInHistory);
   PrefService* local_state = GetLocalStatePrefs();
   if (!local_state) {
@@ skipping 23 matching lines @@
        i < kNumDaysInHistory; ++i) {
     orig += GetInt64PrefValue(*original_list, i);
     recv += GetInt64PrefValue(*received_list, i);
   }
   *original_content_length = orig;
   *received_content_length = recv;
   *last_update_time =
       local_state->GetInt64(prefs::kDailyHttpContentLengthLastUpdateDate);
 }
 
-std::string DataReductionProxySettings::GetProxyCheckURL() {
-  if (!IsDataReductionProxyAllowed())
-    return std::string();
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  if (command_line.HasSwitch(switches::kDataReductionProxyProbeURL)) {
-    return command_line.GetSwitchValueASCII(
-        switches::kDataReductionProxyProbeURL);
-  }
-#if defined(DATA_REDUCTION_PROXY_PROBE_URL)
-  return DATA_REDUCTION_PROXY_PROBE_URL;
-#else
-  return std::string();
-#endif
-}
-
 // static
 base::string16 DataReductionProxySettings::AuthHashForSalt(
     int64 salt,
     const std::string& key) {
-  std::string active_key;
-
-  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
-  if (command_line.HasSwitch(switches::kDataReductionProxy)) {
-    // If an origin is provided via a switch, then only consider the value
-    // that is provided by a switch. Do not use the preprocessor constant.
-    // Don't expose |key_| to a proxy passed in via the command line.
-    if (!command_line.HasSwitch(switches::kDataReductionProxyKey))
-      return base::string16();
-    active_key = command_line.GetSwitchValueASCII(
-        switches::kDataReductionProxyKey);
-  } else {
-    active_key = key;
-  }
-  DCHECK(!active_key.empty());
-
   std::string salted_key =
       base::StringPrintf("%lld%s%lld",
                          static_cast<long long>(salt),
-                         active_key.c_str(),
+                         key.c_str(),
                          static_cast<long long>(salt));
   return base::UTF8ToUTF16(base::MD5String(salted_key));
 }
 
 net::URLFetcher* DataReductionProxySettings::GetURLFetcher() {
   DCHECK(url_request_context_getter_);
-  std::string url = GetProxyCheckURL();
-  if (url.empty())
-    return NULL;
-  net::URLFetcher* fetcher = net::URLFetcher::Create(GURL(url),
+  net::URLFetcher* fetcher = net::URLFetcher::Create(params_->probe_url(),
                                                      net::URLFetcher::GET,
                                                      this);
   fetcher->SetLoadFlags(net::LOAD_DISABLE_CACHE | net::LOAD_BYPASS_PROXY);
   fetcher->SetRequestContext(url_request_context_getter_);
   // Configure max retries to be at most kMaxRetries times for 5xx errors.
   static const int kMaxRetries = 5;
   fetcher->SetMaxRetriesOn5xx(kMaxRetries);
   return fetcher;
 }
 
 void DataReductionProxySettings::ProbeWhetherDataReductionProxyIsAvailable() {
   net::URLFetcher* fetcher = GetURLFetcher();
   if (!fetcher)
     return;
   fetcher_.reset(fetcher);
   fetcher_->Start();
 }
 
 }  // namespace data_reduction_proxy