Add ref count to service workers for extension API.

content/browser/service_worker/service_worker_version.h

Index: content/browser/service_worker/service_worker_version.h
diff --git a/content/browser/service_worker/service_worker_version.h b/content/browser/service_worker/service_worker_version.h
index 5026700bcbe09f5a78f3a83a27c1700d9fe29a70..ff17826518658597412722d91f8bd6e80a82d2df 100644
--- a/content/browser/service_worker/service_worker_version.h
+++ b/content/browser/service_worker/service_worker_version.h
@@ -235,6 +235,11 @@ class CONTENT_EXPORT ServiceWorkerVersion
                                     const base::TimeDelta& timeout,
                                     TimeoutBehavior timeout_behavior);
 
+  // Starts a request of type EventType::EXTERNAL_REQUEST.
+  // Provides a mechanism to external clients to keep the worker running.
+  // |request_uuid| is a GUID for clients to identify the request.
+  bool StartExternalRequest(const std::string& request_uuid);
+
   // Informs ServiceWorkerVersion that an event has finished being dispatched.
   // Returns false if no pending requests with the provided id exist, for
   // example if the request has already timed out.
@@ -245,6 +250,9 @@ class CONTENT_EXPORT ServiceWorkerVersion
                      bool was_handled,
                      base::Time dispatch_event_time);
 
+  // Finishes an external request that was started by StartExternalRequest().
+  bool FinishExternalRequest(const std::string& request_uuid);
+
   // Connects to a specific mojo service exposed by the (running) service
   // worker. If a connection to a service for the same Interface already exists
   // this will return that existing connection. The |request_id| must be a value
@@ -681,6 +689,10 @@ class CONTENT_EXPORT ServiceWorkerVersion
   // callbacks.
   void FinishStartWorker(ServiceWorkerStatusCode status);
 
+  // Removes any pending external request that has GUID of |request_uuid|.
+  void CleanUpExternalRequest(const std::string& request_uuid,
+                              ServiceWorkerStatusCode status);
+
   const int64_t version_id_;
   const int64_t registration_id_;
   const GURL script_url_;
@@ -700,6 +712,11 @@ class CONTENT_EXPORT ServiceWorkerVersion
   // fetch, sync, etc. events.
   IDMap<PendingRequest, IDMapOwnPointer> pending_requests_;
 
+  // Container for pending external requests for this service worker.
+  // (key, value): (request uuid, request id).
+  using RequestUUIDToRequestIDMap = std::map<std::string, int>;
+  RequestUUIDToRequestIDMap external_request_uuid_to_request_id_;
+
   // Stores all open connections to mojo services. Maps the service name to
   // the actual interface pointer. When a connection is closed it is removed
   // from this map.