service worker: Clean up fetch event if URLRequest gets cancelled.

content/browser/service_worker/service_worker_version.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_SERVICE_WORKER_VERSION_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_VERSION_H_
 
 #include <stdint.h>
 
 #include <functional>
@@ skipping 174 matching lines @@
   // Starts the worker if it isn't already running, and calls |task| when the
   // worker is running, or |error_callback| if starting the worker failed.
   // If the worker is already running, |task| is executed synchronously (before
   // this method returns).
   // |purpose| is used for UMA.
   void RunAfterStartWorker(ServiceWorkerMetrics::EventType purpose,
                            const base::Closure& task,
                            const StatusCallback& error_callback);
 
   // Call this while the worker is running before dispatching an event to the
-  // worker. This informs ServiceWorkerVersion about the event in progress.
-  // Returns a request id, which should later be passed to FinishRequest when
-  // the event finished.
+  // worker. This informs ServiceWorkerVersion about the event in progress. The
+  // worker attempts to keep running until the event finishes.
+  //
+  // Returns a request id, which must later be passed to FinishRequest when the
+  // event finished. The caller is responsible for ensuring FinishRequest is
+  // called. If FinishRequest is not called the request will eventually time
+  // out and the worker will be forcibly terminated.
+  //
   // The |error_callback| is called if either ServiceWorkerVersion decides the
   // event is taking too long, or if for some reason the worker stops or is
-  // killed before the request finishes.
+  // killed before the request finishes. In this case, the caller should not
+  // call FinishRequest.
   int StartRequest(ServiceWorkerMetrics::EventType event_type,
                    const StatusCallback& error_callback);
 
   // Same as StartRequest, but allows the caller to specify a custom timeout for
   // the event, as well as the behavior for when the request times out.
   int StartRequestWithCustomTimeout(ServiceWorkerMetrics::EventType event_type,
                                     const StatusCallback& error_callback,
                                     const base::TimeDelta& timeout,
                                     TimeoutBehavior timeout_behavior);
 
@@ skipping 155 matching lines @@
                            TimeoutWorkerInEvent);
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerStallInStoppingTest, DetachThenStart);
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerStallInStoppingTest, DetachThenRestart);
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerVersionTest,
                            RegisterForeignFetchScopes);
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerVersionTest, RequestCustomizedTimeout);
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerVersionTest,
                            RequestCustomizedTimeoutKill);
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerVersionTest, MixedRequestTimeouts);
   FRIEND_TEST_ALL_PREFIXES(ServiceWorkerURLRequestJobTest, EarlyResponse);
+  FRIEND_TEST_ALL_PREFIXES(ServiceWorkerURLRequestJobTest, CancelRequest);
 
   class Metrics;
   class PingController;
 
   struct RequestInfo {
     RequestInfo(int id,
                 ServiceWorkerMetrics::EventType event_type,
                 const base::TimeTicks& expiration,
                 TimeoutBehavior timeout_behavior);
     ~RequestInfo();
@@ skipping 390 matching lines @@
 
   // At this point |this| can have been deleted, so don't do anything other
   // than returning.
 
   return true;
 }
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_VERSION_H_