Only log the job controller count when it's hitting boundaries for the first time

net/http/http_stream_factory_impl.h

 // Copyright (c) 2012 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_HTTP_HTTP_STREAM_FACTORY_IMPL_H_
 #define NET_HTTP_HTTP_STREAM_FACTORY_IMPL_H_
 
 #include <stddef.h>
 
 #include <map>
@@ skipping 156 matching lines @@
   // with privacy mode |privacy_mode| is ready.
   void OnStreamReady(const ProxyInfo& proxy_info, PrivacyMode privacy_mode);
 
   // Returns true if |proxy_info| contains a proxy server that supports request
   // priorities.
   bool ProxyServerSupportsPriorities(const ProxyInfo& proxy_info) const;
 
   // Adds the count of JobControllers that are not completed to UMA histogram if
   // the count is a multiple of 100: 100, 200, 400, etc. Break down
   // JobControllers count based on the type of JobController.
-  void AddJobControllerCountToHistograms() const;
+  void AddJobControllerCountToHistograms();
 
   HttpNetworkSession* const session_;
 
   // All Requests/Preconnects are assigned with a JobController to manage
   // serving Job(s). JobController might outlive Request when Request
   // is served while there's some working Job left. JobController will be
   // deleted from |job_controller_set_| when it determines the completion of
   // its work.
   JobControllerSet job_controller_set_;
 
   // Factory used by job controllers for creating jobs.
   std::unique_ptr<JobFactory> job_factory_;
 
   // Set of proxy servers that support request priorities to which subsequent
   // preconnects should be skipped.
   std::set<PreconnectingProxyServer> preconnecting_proxy_servers_;
 
   SpdySessionRequestMap spdy_session_request_map_;
 
   const bool for_websockets_;
 
+  // The count of JobControllers that was most recently logged to histograms.
+  size_t last_logged_job_controller_count_;
+
   DISALLOW_COPY_AND_ASSIGN(HttpStreamFactoryImpl);
 };
 
 }  // namespace net
 
 #endif  // NET_HTTP_HTTP_STREAM_FACTORY_IMPL_H_