Make call sites of subresource_filter::GetActiveConfigurations const-correct.

components/subresource_filter/core/browser/subresource_filter_features.h

 // 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.
 
 #ifndef COMPONENTS_SUBRESOURCE_FILTER_CORE_BROWSER_SUBRESOURCE_FILTER_FEATURES_H_
 #define COMPONENTS_SUBRESOURCE_FILTER_CORE_BROWSER_SUBRESOURCE_FILTER_FEATURES_H_
 
 #include "base/feature_list.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
@@ skipping 41 matching lines @@
   std::string ruleset_flavor;
 
   // Whether to whitelist a site when a page loaded from that site is reloaded.
   bool should_whitelist_site_on_reload = false;
 };
 
 // TODO(engedy): Make this an actual list once all call sites are prepared to
 // handle multiple simultaneous configurations.
 class ConfigurationList : public base::RefCountedThreadSafe<ConfigurationList> {
  public:
-  ConfigurationList(Configuration config);
+  explicit ConfigurationList(Configuration config);
 
   const Configuration& the_one_and_only() const { return config_; }
 
  private:
   friend class base::RefCountedThreadSafe<ConfigurationList>;
   ~ConfigurationList();
 
   const Configuration config_;
 
   DISALLOW_COPY_AND_ASSIGN(ConfigurationList);
@@ skipping 42 matching lines @@
 
 extern const char kPerformanceMeasurementRateParameterName[];
 
 extern const char kSuppressNotificationsParameterName[];
 
 extern const char kWhitelistSiteOnReloadParameterName[];
 
 }  // namespace subresource_filter
 
 #endif  // COMPONENTS_SUBRESOURCE_FILTER_CORE_BROWSER_SUBRESOURCE_FILTER_FEATURES_H_