Server push cancellation: add a finch trial parameter

components/network_session_configurator/network_session_configurator.cc

Index: components/network_session_configurator/network_session_configurator.cc
diff --git a/components/network_session_configurator/network_session_configurator.cc b/components/network_session_configurator/network_session_configurator.cc
index 91a2b15ab088b14d8e51fb39a5cd09b3d91bb4d1..fba5a01cfee0dd6e6f720fe057be82b3e5070b63 100644
--- a/components/network_session_configurator/network_session_configurator.cc
+++ b/components/network_session_configurator/network_session_configurator.cc
@@ -324,6 +324,13 @@ net::QuicVersion GetQuicVersion(const VariationParameters& quic_trial_params) {
       GetVariationParam(quic_trial_params, "quic_version"));
 }
 
+bool ShouldEnableServerPushCancelation(
+    const VariationParameters& quic_trial_params) {
+  return base::LowerCaseEqualsASCII(
+      GetVariationParam(quic_trial_params, "enable_server_push_cancellation"),
+      "true");
+}
+
 void ConfigureQuicParams(base::StringPiece quic_trial_group,
                          const VariationParameters& quic_trial_params,
                          bool is_quic_force_disabled,
@@ -335,6 +342,8 @@ void ConfigureQuicParams(base::StringPiece quic_trial_group,
       is_quic_force_enabled);
   params->disable_quic_on_timeout_with_open_streams =
       ShouldDisableQuicWhenConnectionTimesOutWithOpenStreams(quic_trial_params);
+  params->enable_server_push_cancellation =
+      ShouldEnableServerPushCancelation(quic_trial_params);
 
   params->enable_quic_alternative_service_with_different_host =
       ShouldQuicEnableAlternativeServicesForDifferentHost(quic_trial_params);