Add ref count to service workers for extension API.

content/public/browser/service_worker_context.h

 // Copyright 2014 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_PUBLIC_BROWSER_SERVICE_WORKER_CONTEXT_H_
 #define CONTENT_PUBLIC_BROWSER_SERVICE_WORKER_CONTEXT_H_
 
 #include <set>
 #include <string>
 
@@ skipping 15 matching lines @@
   typedef GURL Scope;
 
   typedef base::Callback<void(bool success)> ResultCallback;
 
   typedef base::Callback<void(const std::vector<ServiceWorkerUsageInfo>&
                                   usage_info)> GetUsageInfoCallback;
 
   typedef base::Callback<void(bool has_service_worker)>
       CheckHasServiceWorkerCallback;
 
+  typedef base::Callback<void(size_t external_request_count)>
+      CountExternalRequestsCallback;

[Avi (use Gerrit), 2016/10/07 21:33:11]

Can we use the cool new

using CountExternalRequestsCallback = base::Callback<void(size_t
external_request_count)>;

syntax here and above? C++11 style guide calls it out as preferred.

[lazyboy, 2016/10/07 22:31:49]

Done.

+
   // Registers the header name which should not be passed to the ServiceWorker.
   // Must be called from the IO thread.
   CONTENT_EXPORT static void AddExcludedHeadersForFetchEvent(
       const std::set<std::string>& header_names);
 
   // Returns true if the header name should not be passed to the ServiceWorker.
   // Must be called from the IO thread.
   static bool IsExcludedHeaderNameForFetchEvent(const std::string& header_name);
 
   // Equivalent to calling navigator.serviceWorker.register(script_url, {scope:
   // pattern}) from a renderer, except that |pattern| is an absolute URL instead
   // of relative to some current origin.  |callback| is passed true when the JS
   // promise is fulfilled or false when the JS promise is rejected.
   //
   // The registration can fail if:
   //  * |script_url| is on a different origin from |pattern|
   //  * Fetching |script_url| fails.
   //  * |script_url| fails to parse or its top-level execution fails.
   //    TODO: The error message for this needs to be available to developers.
   //  * Something unexpected goes wrong, like a renderer crash or a full disk.
   //
   // This function can be called from any thread, but the callback will always
   // be called on the UI thread.
   virtual void RegisterServiceWorker(const Scope& pattern,
                                      const GURL& script_url,
                                      const ResultCallback& callback) = 0;
 
+  // Mechanism for embedder to increment/decrement ref count of a service
+  // worker.
+  // Embedders can call StartingExternalRequest() while it is performing some
+  // work with the worker. The worker is considered to be working until embedder
+  // calls FinishedExternalRequest(). This ensures that content/ does not
+  // shut the worker down while embedder is expecting the worker to be kept
+  // alive.
+  //
+  // Must be called from the IO thread. Returns whether or not changing the ref
+  // count succeeded.
+  virtual bool StartingExternalRequest(int64_t service_worker_version_id,
+                                       const std::string& request_uuid) = 0;
+  virtual bool FinishedExternalRequest(int64_t service_worker_version_id,
+                                       const std::string& request_uuid) = 0;
+
   // Equivalent to calling navigator.serviceWorker.unregister(pattern) from a
   // renderer, except that |pattern| is an absolute URL instead of relative to
   // some current origin.  |callback| is passed true when the JS promise is
   // fulfilled or false when the JS promise is rejected.
   //
   // Unregistration can fail if:
   //  * No Service Worker was registered for |pattern|.
   //  * Something unexpected goes wrong, like a renderer crash.
   //
   // This function can be called from any thread, but the callback will always
@@ skipping 16 matching lines @@
   // this still returns true even if there is a Service Worker registration
   // which has a longer match for |other_url|.
   //
   // This function can be called from any thread, but the callback will always
   // be called on the UI thread.
   virtual void CheckHasServiceWorker(
       const GURL& url,
       const GURL& other_url,
       const CheckHasServiceWorkerCallback& callback) = 0;
 
+  // Returns the pending external request count for the worker with the
+  // specified |origin| via |callback|.
+  virtual void CountExternalRequestsForTest(
+      const GURL& origin,
+      const CountExternalRequestsCallback& callback) = 0;
+
   // Stops all running workers on the given |origin|.
   //
   // This function can be called from any thread.
   virtual void StopAllServiceWorkersForOrigin(const GURL& origin) = 0;
 
   // Stops all running service workers and unregisters all service worker
   // registrations. This method is used in LayoutTests to make sure that the
   // existing service worker will not affect the succeeding tests.
   //
   // This function can be called from any thread, but the callback will always
@@ skipping 13 matching lines @@
       const ResultCallback& callback) = 0;
 
  protected:
   ServiceWorkerContext() {}
   virtual ~ServiceWorkerContext() {}
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_SERVICE_WORKER_CONTEXT_H_