Reporting: Document browsing data remover + endpoint backoff

net/reporting/reporting_endpoint_manager.h

 // Copyright 2017 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 NET_REPORTING_REPORTING_ENDPOINT_MANAGER_H_
 #define NET_REPORTING_REPORTING_ENDPOINT_MANAGER_H_
 
 #include <map>
 #include <memory>
 #include <set>
@@ skipping 54 matching lines @@
   void InformOfEndpointRequest(const GURL& endpoint, bool succeeded);
 
  private:
   const ReportingPolicy& policy() { return context_->policy(); }
   base::TickClock* tick_clock() { return context_->tick_clock(); }
   ReportingCache* cache() { return context_->cache(); }
 
   ReportingContext* context_;
 
   std::set<GURL> pending_endpoints_;
+
+  // Note: Currently the ReportingBrowsingDataRemover does not clear this data
+  // because it's not persisted to disk. If it's ever persisted, it will need
+  // to be cleared as well.
   std::map<GURL, std::unique_ptr<net::BackoffEntry>> endpoint_backoff_;
 
   DISALLOW_COPY_AND_ASSIGN(ReportingEndpointManager);
 };
 
 }  // namespace net
 
 #endif  // NET_REPORTING_REPORTING_ENDPOINT_MANAGER_H_