Add ref count to service workers for extension API.

content/browser/service_worker/service_worker_context_wrapper.h

Index: content/browser/service_worker/service_worker_context_wrapper.h
diff --git a/content/browser/service_worker/service_worker_context_wrapper.h b/content/browser/service_worker/service_worker_context_wrapper.h
index 12c8b7220cd833464c774c76357a7bb6408573c5..b8dfb1e3733edcee9ad09e3ec9d121bbb41fcaad 100644
--- a/content/browser/service_worker/service_worker_context_wrapper.h
+++ b/content/browser/service_worker/service_worker_context_wrapper.h
@@ -112,6 +112,8 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
       blink::WebNavigationHintType type,
       int render_process_id,
       const ResultCallback& callback) override;
+  bool IncrementPendingActivity(int64_t service_worker_version_id) override;
+  bool DecrementPendingActivity(int64_t service_worker_version_id) override;
 
   // These methods must only be called from the IO thread.
   ServiceWorkerRegistration* GetLiveRegistration(int64_t registration_id);
@@ -196,6 +198,7 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
   friend class base::RefCountedThreadSafe<ServiceWorkerContextWrapper>;
   friend class EmbeddedWorkerTestHelper;
   friend class EmbeddedWorkerBrowserTest;
+  friend class ServiceWorkerContext;
   friend class ServiceWorkerDispatcherHost;
   friend class ServiceWorkerInternalsUI;
   friend class ServiceWorkerNavigationHandleCore;
@@ -256,6 +259,9 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
                                        const ResultCallback& callback,
                                        bool result);
 
+  void ExternalRequestErrorCallback(int64_t service_worker_version_id,
+                                    ServiceWorkerStatusCode status);
+
   // The core context is only for use on the IO thread.
   // Can be null before/during init, during/after shutdown, and after
   // DeleteAndStartOver fails.
@@ -279,6 +285,11 @@ class CONTENT_EXPORT ServiceWorkerContextWrapper
   // Must be touched on the UI thread.
   std::map<int, int> navigation_hint_task_count_per_process_;
 
+  // Maps service worker version id -> list of pending request ids in the order
+  // they arrive.
+  // IO thread.
+  std::map<int64_t, std::queue<int>> pending_external_requests_;
+
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerContextWrapper);
 };