Split the ScopedSubresourceFilterFeatureToggle into two helper classes.

components/subresource_filter/core/browser/subresource_filter_features.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/subresource_filter/core/browser/subresource_filter_features.h"
 
 #include <string>
 #include <utility>
 
 #include "base/lazy_instance.h"
@@ skipping 135 matching lines @@
 const char kRulesetFlavorParameterName[] = "ruleset_flavor";
 
 const char kPerformanceMeasurementRateParameterName[] =
     "performance_measurement_rate";
 
 const char kSuppressNotificationsParameterName[] = "suppress_notifications";
 
 const char kWhitelistSiteOnReloadParameterName[] = "whitelist_site_on_reload";
 
 Configuration::Configuration() = default;
+Configuration::Configuration(ActivationLevel activation_level,
+                             ActivationScope activation_scope,
+                             ActivationList activation_list)
+    : activation_level(activation_level),
+      activation_scope(activation_scope),
+      activation_list(activation_list) {}
+Configuration::Configuration(Configuration&&) = default;
 Configuration::~Configuration() = default;
-Configuration::Configuration(Configuration&&) = default;
 Configuration& Configuration::operator=(Configuration&&) = default;
 
 ConfigurationList::ConfigurationList(Configuration config)
     : config_(std::move(config)) {}
 ConfigurationList::~ConfigurationList() = default;
 
 scoped_refptr<ConfigurationList> GetActiveConfigurations() {
   base::AutoLock lock(g_active_configurations_lock.Get());
   if (!g_active_configurations.Get()) {
     g_active_configurations.Get() =
         base::MakeShared<ConfigurationList>(ParseFieldTrialConfiguration());
   }
   return g_active_configurations.Get();
 }
 
 namespace testing {
 
-void ClearCachedActiveConfigurations() {
+scoped_refptr<ConfigurationList> GetAndSetActivateConfigurations(
+    scoped_refptr<ConfigurationList> new_configs) {
   base::AutoLock lock(g_active_configurations_lock.Get());
-  g_active_configurations.Get() = nullptr;
+  auto old_configs = std::move(g_active_configurations.Get());
+  g_active_configurations.Get() = std::move(new_configs);
+  return old_configs;
 }
 
 }  // namespace testing
 
 }  // namespace subresource_filter