Add components/network_session_configurator.

components/network_session_configurator/network_session_configurator.cc

+// Copyright (c) 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"
+#include "base/strings/string_piece.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
+#include "components/network_session_configurator/switches.h"
+#include "components/variations/variations_associated_data.h"
+#include "components/version_info/version_info.h"
+#include "net/http/http_stream_factory.h"
+#include "net/quic/quic_protocol.h"
+#include "net/quic/quic_utils.h"
+#include "net/url_request/url_fetcher.h"
+
+namespace {
+
+// Map from name to value for all parameters associate with a field trial.
+using VariationParameters = std::map<std::string, std::string>;
+
+const char kTCPFastOpenFieldTrialName[] = "TCPFastOpen";
+const char kTCPFastOpenHttpsEnabledGroupName[] = "HttpsEnabled";
+
+const char kQuicFieldTrialName[] = "QUIC";
+const char kQuicFieldTrialEnabledGroupName[] = "Enabled";
+const char kQuicFieldTrialHttpsEnabledGroupName[] = "HttpsEnabled";
+
+// The SPDY trial composes two different trial plus control groups:
+//  * A "holdback" group with SPDY disabled, and corresponding control
+//  (SPDY/3.1). The primary purpose of the holdback group is to encourage site
+//  operators to do feature detection rather than UA-sniffing. As such, this
+//  trial runs continuously.
+//  * A SPDY/4 experiment, for SPDY/4 (aka HTTP/2) vs SPDY/3.1 comparisons and
+//  eventual SPDY/4 deployment.
+const char kSpdyFieldTrialName[] = "SPDY";
+const char kSpdyFieldTrialHoldbackGroupNamePrefix[] = "SpdyDisabled";
+const char kSpdyFieldTrialSpdy31GroupNamePrefix[] = "Spdy31Enabled";
+const char kSpdyFieldTrialSpdy4GroupNamePrefix[] = "Spdy4Enabled";
+const char kSpdyFieldTrialParametrizedPrefix[] = "Parametrized";
+
+// The AltSvc trial controls whether Alt-Svc headers are parsed.
+// Disabled:
+//     Alt-Svc headers are not parsed.
+//     Alternate-Protocol headers are parsed.
+// Enabled:
+//     Alt-Svc headers are parsed, but only same-host entries are used by
+//     default.  (Use "enable_alternative_service_with_different_host" QUIC
+//     parameter to enable entries with different hosts.)
+//     Alternate-Protocol headers are ignored for responses that have an Alt-Svc
+//     header.
+const char kAltSvcFieldTrialName[] = "ParseAltSvc";
+const char kAltSvcFieldTrialDisabledPrefix[] = "AltSvcDisabled";
+const char kAltSvcFieldTrialEnabledPrefix[] = "AltSvcEnabled";
+
+// Field trial for NPN.
+const char kNpnTrialName[] = "NPN";
+const char kNpnTrialEnabledGroupNamePrefix[] = "Enable";
+const char kNpnTrialDisabledGroupNamePrefix[] = "Disable";
+
+// Field trial for priority dependencies.
+const char kSpdyDependenciesFieldTrial[] = "SpdyEnableDependencies";
+const char kSpdyDependenciesFieldTrialEnable[] = "Enable";
+const char kSpdyDepencenciesFieldTrialDisable[] = "Disable";
+
+int GetSwitchValueAsInt(const base::CommandLine& command_line,
+                        const std::string& switch_name) {
+  int value;
+  if (!base::StringToInt(command_line.GetSwitchValueASCII(switch_name),
+                         &value)) {
+    return 0;
+  }
+  return value;
+}
+
+// Returns the value associated with |key| in |params| or "" if the
+// key is not present in the map.
+const std::string& GetVariationParam(
+    const std::map<std::string, std::string>& params,
+    const std::string& key) {
+  std::map<std::string, std::string>::const_iterator it = params.find(key);
+  if (it == params.end())
+    return base::EmptyString();
+
+  return it->second;
+}
+
+void ConfigureTCPFastOpenParams(base::StringPiece tfo_trial_group,
+                                net::HttpNetworkSession::Params* params) {
+  if (tfo_trial_group == kTCPFastOpenHttpsEnabledGroupName)
+    params->enable_tcp_fast_open_for_ssl = true;
+}
+
+void ConfigureSpdyParams(const base::CommandLine& command_line,
+                         base::StringPiece spdy_trial_group,
+                         const VariationParameters& spdy_trial_params,
+                         bool is_spdy_allowed_by_policy,
+                         net::HttpNetworkSession::Params* params) {
+  // Only handle SPDY field trial parameters and command line flags if
+  // "spdy.disabled" preference is not forced via policy.
+  if (!is_spdy_allowed_by_policy) {
+    params->enable_spdy31 = false;
+    params->enable_http2 = false;
+    return;
+  }
+
+  if (command_line.HasSwitch(switches::kIgnoreUrlFetcherCertRequests))
+    net::URLFetcher::SetIgnoreCertificateRequests(true);
+
+  if (command_line.HasSwitch(switches::kDisableHttp2)) {
+    params->enable_spdy31 = false;
+    params->enable_http2 = false;
+    return;
+  }
+
+  if (spdy_trial_group.starts_with(kSpdyFieldTrialHoldbackGroupNamePrefix)) {
+    net::HttpStreamFactory::set_spdy_enabled(false);
+    return;
+  }
+  if (spdy_trial_group.starts_with(kSpdyFieldTrialSpdy31GroupNamePrefix)) {
+    params->enable_spdy31 = true;
+    params->enable_http2 = false;
+    return;
+  }
+  if (spdy_trial_group.starts_with(kSpdyFieldTrialSpdy4GroupNamePrefix)) {
+    params->enable_spdy31 = true;
+    params->enable_http2 = true;
+    return;
+  }
+  if (spdy_trial_group.starts_with(kSpdyFieldTrialParametrizedPrefix)) {
+    bool spdy_enabled = false;
+    params->enable_spdy31 = false;
+    params->enable_http2 = false;
+    if (base::LowerCaseEqualsASCII(
+            GetVariationParam(spdy_trial_params, "enable_http2"), "true")) {
+      spdy_enabled = true;
+      params->enable_http2 = true;
+    }
+    if (base::LowerCaseEqualsASCII(
+            GetVariationParam(spdy_trial_params, "enable_spdy31"), "true")) {
+      spdy_enabled = true;
+      params->enable_spdy31 = true;
+    }
+    // TODO(bnc): https://crbug.com/521597
+    // HttpStreamFactory::spdy_enabled_ is redundant with params->enable_http2
+    // and enable_spdy31, can it be eliminated?
+    net::HttpStreamFactory::set_spdy_enabled(spdy_enabled);
+    return;
+  }
+}
+
+void ConfigureAltSvcParams(const base::CommandLine& command_line,
+                           base::StringPiece altsvc_trial_group,
+                           net::HttpNetworkSession::Params* params) {
+  if (command_line.HasSwitch(switches::kEnableAlternativeServices) ||
+      altsvc_trial_group.starts_with(kAltSvcFieldTrialEnabledPrefix)) {
+    params->parse_alternative_services = true;
+    return;
+  }
+  if (altsvc_trial_group.starts_with(kAltSvcFieldTrialDisabledPrefix)) {
+    params->parse_alternative_services = false;
+  }
+}
+
+void ConfigureNPNParams(const base::CommandLine& command_line,
+                        base::StringPiece npn_trial_group,
+                        net::HttpNetworkSession::Params* params) {
+  if (npn_trial_group.starts_with(kNpnTrialEnabledGroupNamePrefix)) {
+    params->enable_npn = true;
+  } else if (npn_trial_group.starts_with(kNpnTrialDisabledGroupNamePrefix)) {
+    params->enable_npn = false;
+  }
+}
+
+void ConfigurePriorityDependencies(
+    base::StringPiece priority_dependencies_trial_group,
+    net::HttpNetworkSession::Params* params) {
+  if (priority_dependencies_trial_group.starts_with(
+          kSpdyDependenciesFieldTrialEnable)) {
+    params->enable_priority_dependencies = true;
+  } else if (priority_dependencies_trial_group.starts_with(
+                 kSpdyDepencenciesFieldTrialDisable)) {
+    params->enable_priority_dependencies = false;
+  }
+}
+
+bool ShouldEnableQuic(const base::CommandLine& command_line,
+                      base::StringPiece quic_trial_group,
+                      bool is_quic_allowed_by_policy) {
+  if (command_line.HasSwitch(switches::kDisableQuic) ||
+      !is_quic_allowed_by_policy)
+    return false;
+
+  if (command_line.HasSwitch(switches::kEnableQuic))
+    return true;
+
+  return quic_trial_group.starts_with(kQuicFieldTrialEnabledGroupName) ||
+         quic_trial_group.starts_with(kQuicFieldTrialHttpsEnabledGroupName);
+}
+
+bool ShouldEnableQuicForProxies(const base::CommandLine& command_line,
+                                base::StringPiece quic_trial_group,
+                                bool is_quic_allowed_by_policy) {
+  return ShouldEnableQuic(command_line, quic_trial_group,
+                          is_quic_allowed_by_policy) ||
+         network_session_configurator::ShouldEnableQuicForDataReductionProxy(
+             command_line);
+}
+
+bool ShouldDisableQuicWhenConnectionTimesOutWithOpenStreams(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params,
+                        "disable_quic_on_timeout_with_open_streams"),
+      "true");
+}
+
+bool ShouldQuicDisableConnectionPooling(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "disable_connection_pooling"),
+      "true");
+}
+
+bool ShouldQuicEnableAlternativeServicesForDifferentHost(
+    const base::CommandLine& command_line,
+    const VariationParameters& quic_trial_params) {
+  // TODO(bnc): Remove inaccurately named "use_alternative_services" parameter.
+  return command_line.HasSwitch(switches::kEnableAlternativeServices) ||
+         base::LowerCaseEqualsASCII(
+             GetVariationParam(quic_trial_params, "use_alternative_services"),
+             "true") ||
+         base::LowerCaseEqualsASCII(
+             GetVariationParam(
+                 quic_trial_params,
+                 "enable_alternative_service_with_different_host"),
+             "true");
+}
+
+bool ShouldEnableQuicPortSelection(const base::CommandLine& command_line) {
+  if (command_line.HasSwitch(switches::kDisableQuicPortSelection))
+    return false;
+
+  if (command_line.HasSwitch(switches::kEnableQuicPortSelection))
+    return true;
+
+  return false;  // Default to disabling port selection on all channels.
+}
+
+net::QuicTagVector GetQuicConnectionOptions(
+    const base::CommandLine& command_line,
+    const VariationParameters& quic_trial_params) {
+  if (command_line.HasSwitch(switches::kQuicConnectionOptions)) {
+    return net::QuicUtils::ParseQuicConnectionOptions(
+        command_line.GetSwitchValueASCII(switches::kQuicConnectionOptions));
+  }
+
+  VariationParameters::const_iterator it =
+      quic_trial_params.find("connection_options");
+  if (it == quic_trial_params.end()) {
+    return net::QuicTagVector();
+  }
+
+  return net::QuicUtils::ParseQuicConnectionOptions(it->second);
+}
+
+bool ShouldQuicAlwaysRequireHandshakeConfirmation(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params,
+                        "always_require_handshake_confirmation"),
+      "true");
+}
+
+float GetQuicLoadServerInfoTimeoutSrttMultiplier(
+    const VariationParameters& quic_trial_params) {
+  double value;
+  if (base::StringToDouble(
+          GetVariationParam(quic_trial_params, "load_server_info_time_to_srtt"),
+          &value)) {
+    return static_cast<float>(value);
+  }
+  return 0.0f;
+}
+
+bool ShouldQuicEnableConnectionRacing(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "enable_connection_racing"), "true");
+}
+
+bool ShouldQuicEnableNonBlockingIO(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "enable_non_blocking_io"), "true");
+}
+
+bool ShouldQuicDisableDiskCache(const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "disable_disk_cache"), "true");
+}
+
+bool ShouldQuicPreferAes(const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "prefer_aes"), "true");
+}
+
+int GetQuicMaxNumberOfLossyConnections(
+    const VariationParameters& quic_trial_params) {
+  int value;
+  if (base::StringToInt(GetVariationParam(quic_trial_params,
+                                          "max_number_of_lossy_connections"),
+                        &value)) {
+    return value;
+  }
+  return 0;
+}
+
+float GetQuicPacketLossThreshold(const VariationParameters& quic_trial_params) {
+  double value;
+  if (base::StringToDouble(
+          GetVariationParam(quic_trial_params, "packet_loss_threshold"),
+          &value)) {
+    return static_cast<float>(value);
+  }
+  return 0.0f;
+}
+
+int GetQuicSocketReceiveBufferSize(
+    const VariationParameters& quic_trial_params) {
+  int value;
+  if (base::StringToInt(
+          GetVariationParam(quic_trial_params, "receive_buffer_size"),
+          &value)) {
+    return value;
+  }
+  return 0;
+}
+
+bool ShouldQuicDelayTcpRace(const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "delay_tcp_race"), "true");
+}
+
+bool ShouldQuicCloseSessionsOnIpChange(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "close_sessions_on_ip_change"),
+      "true");
+}
+
+int GetQuicIdleConnectionTimeoutSeconds(
+    const VariationParameters& quic_trial_params) {
+  int value;
+  if (base::StringToInt(GetVariationParam(quic_trial_params,
+                                          "idle_connection_timeout_seconds"),
+                        &value)) {
+    return value;
+  }
+  return 0;
+}
+
+bool ShouldQuicDisablePreConnectIfZeroRtt(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "disable_preconnect_if_0rtt"),
+      "true");
+}
+
+std::unordered_set<std::string> GetQuicHostWhitelist(
+    const base::CommandLine& command_line,
+    const VariationParameters& quic_trial_params) {
+  std::string whitelist;
+  if (command_line.HasSwitch(switches::kQuicHostWhitelist)) {
+    whitelist = command_line.GetSwitchValueASCII(switches::kQuicHostWhitelist);
+  } else {
+    whitelist = GetVariationParam(quic_trial_params, "quic_host_whitelist");
+  }
+  std::unordered_set<std::string> hosts;
+  for (const std::string& host : base::SplitString(
+           whitelist, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
+    hosts.insert(host);
+  }
+  return hosts;
+}
+
+bool ShouldQuicMigrateSessionsOnNetworkChange(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params,
+                        "migrate_sessions_on_network_change"),
+      "true");
+}
+
+bool ShouldQuicMigrateSessionsEarly(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "migrate_sessions_early"), "true");
+}
+
+size_t GetQuicMaxPacketLength(const base::CommandLine& command_line,
+                              const VariationParameters& quic_trial_params) {
+  if (command_line.HasSwitch(switches::kQuicMaxPacketLength)) {
+    unsigned value;
+    if (!base::StringToUint(
+            command_line.GetSwitchValueASCII(switches::kQuicMaxPacketLength),
+            &value)) {
+      return 0;
+    }
+    return value;
+  }
+
+  unsigned value;
+  if (base::StringToUint(
+          GetVariationParam(quic_trial_params, "max_packet_length"), &value)) {
+    return value;
+  }
+  return 0;
+}
+
+net::QuicVersion ParseQuicVersion(const std::string& quic_version) {
+  net::QuicVersionVector supported_versions = net::QuicSupportedVersions();
+  for (size_t i = 0; i < supported_versions.size(); ++i) {
+    net::QuicVersion version = supported_versions[i];
+    if (net::QuicVersionToString(version) == quic_version) {
+      return version;
+    }
+  }
+
+  return net::QUIC_VERSION_UNSUPPORTED;
+}
+
+net::QuicVersion GetQuicVersion(const base::CommandLine& command_line,
+                                const VariationParameters& quic_trial_params) {
+  if (command_line.HasSwitch(switches::kQuicVersion)) {
+    return ParseQuicVersion(
+        command_line.GetSwitchValueASCII(switches::kQuicVersion));
+  }
+
+  return ParseQuicVersion(GetVariationParam(quic_trial_params, "quic_version"));
+}
+
+void ConfigureQuicParams(const base::CommandLine& command_line,
+                         base::StringPiece quic_trial_group,
+                         const VariationParameters& quic_trial_params,
+                         bool is_quic_allowed_by_policy,
+                         const std::string& quic_user_agent_id,
+                         net::HttpNetworkSession::Params* params) {
+  params->enable_quic = ShouldEnableQuic(command_line, quic_trial_group,
+                                         is_quic_allowed_by_policy);
+  params->disable_quic_on_timeout_with_open_streams =
+      ShouldDisableQuicWhenConnectionTimesOutWithOpenStreams(quic_trial_params);
+  params->enable_quic_for_proxies = ShouldEnableQuicForProxies(
+      command_line, quic_trial_group, is_quic_allowed_by_policy);
+
+  if (ShouldQuicEnableAlternativeServicesForDifferentHost(command_line,
+                                                          quic_trial_params)) {
+    params->enable_alternative_service_with_different_host = true;
+    params->parse_alternative_services = true;
+  } else {
+    params->enable_alternative_service_with_different_host = false;
+  }
+
+  if (params->enable_quic) {
+    params->quic_always_require_handshake_confirmation =
+        ShouldQuicAlwaysRequireHandshakeConfirmation(quic_trial_params);
+    params->quic_disable_connection_pooling =
+        ShouldQuicDisableConnectionPooling(quic_trial_params);
+    int receive_buffer_size = GetQuicSocketReceiveBufferSize(quic_trial_params);
+    if (receive_buffer_size != 0) {
+      params->quic_socket_receive_buffer_size = receive_buffer_size;
+    }
+    params->quic_delay_tcp_race = ShouldQuicDelayTcpRace(quic_trial_params);
+    float load_server_info_timeout_srtt_multiplier =
+        GetQuicLoadServerInfoTimeoutSrttMultiplier(quic_trial_params);
+    if (load_server_info_timeout_srtt_multiplier != 0) {
+      params->quic_load_server_info_timeout_srtt_multiplier =
+          load_server_info_timeout_srtt_multiplier;
+    }
+    params->quic_enable_connection_racing =
+        ShouldQuicEnableConnectionRacing(quic_trial_params);
+    params->quic_enable_non_blocking_io =
+        ShouldQuicEnableNonBlockingIO(quic_trial_params);
+    params->quic_disable_disk_cache =
+        ShouldQuicDisableDiskCache(quic_trial_params);
+    params->quic_prefer_aes = ShouldQuicPreferAes(quic_trial_params);
+    int max_number_of_lossy_connections =
+        GetQuicMaxNumberOfLossyConnections(quic_trial_params);
+    if (max_number_of_lossy_connections != 0) {
+      params->quic_max_number_of_lossy_connections =
+          max_number_of_lossy_connections;
+    }
+    float packet_loss_threshold = GetQuicPacketLossThreshold(quic_trial_params);
+    if (packet_loss_threshold != 0)
+      params->quic_packet_loss_threshold = packet_loss_threshold;
+    params->enable_quic_port_selection =
+        ShouldEnableQuicPortSelection(command_line);
+    params->quic_connection_options =
+        GetQuicConnectionOptions(command_line, quic_trial_params);
+    params->quic_close_sessions_on_ip_change =
+        ShouldQuicCloseSessionsOnIpChange(quic_trial_params);
+    int idle_connection_timeout_seconds =
+        GetQuicIdleConnectionTimeoutSeconds(quic_trial_params);
+    if (idle_connection_timeout_seconds != 0) {
+      params->quic_idle_connection_timeout_seconds =
+          idle_connection_timeout_seconds;
+    }
+    params->quic_disable_preconnect_if_0rtt =
+        ShouldQuicDisablePreConnectIfZeroRtt(quic_trial_params);
+    params->quic_host_whitelist =
+        GetQuicHostWhitelist(command_line, quic_trial_params);
+    params->quic_migrate_sessions_on_network_change =
+        ShouldQuicMigrateSessionsOnNetworkChange(quic_trial_params);
+    params->quic_migrate_sessions_early =
+        ShouldQuicMigrateSessionsEarly(quic_trial_params);
+  }
+
+  size_t max_packet_length =
+      GetQuicMaxPacketLength(command_line, quic_trial_params);
+  if (max_packet_length != 0) {
+    params->quic_max_packet_length = max_packet_length;
+  }
+
+  params->quic_user_agent_id = quic_user_agent_id;
+
+  net::QuicVersion version = GetQuicVersion(command_line, quic_trial_params);
+  if (version != net::QUIC_VERSION_UNSUPPORTED) {
+    net::QuicVersionVector supported_versions;
+    supported_versions.push_back(version);
+    params->quic_supported_versions = supported_versions;
+  }
+
+  if (command_line.HasSwitch(switches::kOriginToForceQuicOn)) {
+    std::string origins =
+        command_line.GetSwitchValueASCII(switches::kOriginToForceQuicOn);
+    for (const std::string& host_port : base::SplitString(
+             origins, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
+      net::HostPortPair quic_origin = net::HostPortPair::FromString(host_port);
+      if (!quic_origin.IsEmpty())
+        params->origins_to_force_quic_on.insert(quic_origin);
+    }
+  }
+}
+
+void ParseFieldTrialsAndCommandLineInternal(
+    const base::CommandLine& command_line,
+    bool is_spdy_allowed_by_policy,
+    bool is_quic_allowed_by_policy,
+    const std::string& quic_user_agent_id,
+    net::HttpNetworkSession::Params* params) {
+  // Parameters only controlled by command line.
+  if (command_line.HasSwitch(switches::kIgnoreCertificateErrors))
+    params->ignore_certificate_errors = true;
+  if (command_line.HasSwitch(switches::kTestingFixedHttpPort)) {
+    params->testing_fixed_http_port =
+        GetSwitchValueAsInt(command_line, switches::kTestingFixedHttpPort);
+  }
+  if (command_line.HasSwitch(switches::kTestingFixedHttpsPort)) {
+    params->testing_fixed_https_port =
+        GetSwitchValueAsInt(command_line, switches::kTestingFixedHttpsPort);
+  }
+
+  // Always fetch the field trial groups to ensure they are reported correctly.
+  // The command line flags will be associated with a group that is reported so
+  // long as trial is actually queried.
+
+  std::string altsvc_trial_group =
+      base::FieldTrialList::FindFullName(kAltSvcFieldTrialName);
+  ConfigureAltSvcParams(command_line, altsvc_trial_group, params);
+
+  std::string quic_trial_group =
+      base::FieldTrialList::FindFullName(kQuicFieldTrialName);
+  VariationParameters quic_trial_params;
+  if (!variations::GetVariationParams(kQuicFieldTrialName, &quic_trial_params))
+    quic_trial_params.clear();
+  ConfigureQuicParams(command_line, quic_trial_group, quic_trial_params,
+                      is_quic_allowed_by_policy, quic_user_agent_id, params);
+
+  if (!is_spdy_allowed_by_policy) {
+    base::FieldTrial* trial = base::FieldTrialList::Find(kSpdyFieldTrialName);
+    if (trial)
+      trial->Disable();
+  }
+  std::string spdy_trial_group =
+      base::FieldTrialList::FindFullName(kSpdyFieldTrialName);
+  VariationParameters spdy_trial_params;
+  if (!variations::GetVariationParams(kSpdyFieldTrialName, &spdy_trial_params))
+    spdy_trial_params.clear();
+  ConfigureSpdyParams(command_line, spdy_trial_group, spdy_trial_params,
+                      is_spdy_allowed_by_policy, params);
+
+  const std::string tfo_trial_group =
+      base::FieldTrialList::FindFullName(kTCPFastOpenFieldTrialName);
+  ConfigureTCPFastOpenParams(tfo_trial_group, params);
+
+  std::string npn_trial_group =
+      base::FieldTrialList::FindFullName(kNpnTrialName);
+  ConfigureNPNParams(command_line, npn_trial_group, params);
+
+  std::string priority_dependencies_trial_group =
+      base::FieldTrialList::FindFullName(kSpdyDependenciesFieldTrial);
+  ConfigurePriorityDependencies(priority_dependencies_trial_group, params);
+}
+
+}  // anonymous namespace
+
+namespace network_session_configurator {
+
+void ParseFieldTrials(bool is_spdy_allowed_by_policy,
+                      bool is_quic_allowed_by_policy,
+                      const std::string& quic_user_agent_id,
+                      net::HttpNetworkSession::Params* params) {
+  const base::CommandLine command_line(base::CommandLine::NO_PROGRAM);
+  ParseFieldTrialsAndCommandLineInternal(
+      command_line, is_spdy_allowed_by_policy, is_quic_allowed_by_policy,
+      quic_user_agent_id, params);
+}
+
+void ParseFieldTrialsAndCommandLine(bool is_spdy_allowed_by_policy,
+                                    bool is_quic_allowed_by_policy,
+                                    const std::string& quic_user_agent_id,
+                                    net::HttpNetworkSession::Params* params) {
+  const base::CommandLine& command_line =
+      *base::CommandLine::ForCurrentProcess();
+  ParseFieldTrialsAndCommandLineInternal(
+      command_line, is_spdy_allowed_by_policy, is_quic_allowed_by_policy,
+      quic_user_agent_id, params);
+}
+
+bool ShouldEnableQuicForDataReductionProxy(
+    const base::CommandLine& command_line) {
+  if (command_line.HasSwitch(switches::kDisableQuic))
+    return false;
+
+  return data_reduction_proxy::params::IsIncludedInQuicFieldTrial();
+}
+
+}  // namespace network_session_configurator