Add ref count to service workers for extension API.

content/browser/service_worker/embedded_worker_instance.h

 // Copyright 2013 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 CONTENT_BROWSER_SERVICE_WORKER_EMBEDDED_WORKER_INSTANCE_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_EMBEDDED_WORKER_INSTANCE_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 178 matching lines @@
 
   // Add message to the devtools console.
   void AddMessageToConsole(ConsoleMessageLevel level,
                            const std::string& message);
 
   static std::string StatusToString(EmbeddedWorkerStatus status);
   static std::string StartingPhaseToString(StartingPhase phase);
 
   void Detach();
 
+  void IncrementRefCount();
+  void DecrementRefCount();

[falken, 2016/07/22 05:06:01]

ref count is kind of generic, maybe "IncrementPendingActivity" would be more
clear that this affects StopIfIdle.

[lazyboy, 2016/07/26 17:45:48]

Done.

+
   base::WeakPtr<EmbeddedWorkerInstance> AsWeakPtr();
 
  private:
   typedef base::ObserverList<Listener> ListenerList;
   class DevToolsProxy;
   class StartTask;
   class WorkerProcessHandle;
   friend class EmbeddedWorkerRegistry;
   FRIEND_TEST_ALL_PREFIXES(EmbeddedWorkerInstanceTest, StartAndStop);
   FRIEND_TEST_ALL_PREFIXES(EmbeddedWorkerInstanceTest, DetachDuringStart);
@@ skipping 108 matching lines @@
 
   std::unique_ptr<StartTask> inflight_start_task_;
 
   // This is valid only after a process is allocated for the worker.
   ServiceWorkerMetrics::StartSituation start_situation_ =
       ServiceWorkerMetrics::StartSituation::UNKNOWN;
 
   // Used for UMA. The start time of the current start sequence step.
   base::TimeTicks step_time_;
 
+  int external_ref_count_;
+
   base::WeakPtrFactory<EmbeddedWorkerInstance> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(EmbeddedWorkerInstance);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_EMBEDDED_WORKER_INSTANCE_H_