After 24 hours, bust the browser cache when checking for ServiceWorker updates

content/browser/service_worker/service_worker_registration.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_REGISTRATION_H_
 #define CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_REGISTRATION_H_
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "base/logging.h"
@@ skipping 82 matching lines @@
   // Triggers the [[ClearRegistration]] algorithm when the currently
   // active version has no controllees. Deletes this registration
   // from storage immediately.
   void ClearWhenReady();
 
   // Restores this registration in storage and cancels the pending
   // [[ClearRegistration]] algorithm. If the algorithm was already triggered,
   // does nothing.
   void AbortPendingClear();
 
+  // The time of the most recent update check.
+  base::Time last_update_check() const { return last_update_check_; }
+  void set_last_update_check(base::Time last) { last_update_check_ = last; }
+
  private:
   friend class base::RefCounted<ServiceWorkerRegistration>;
 
   virtual ~ServiceWorkerRegistration();
 
   void SetVersionInternal(
       ServiceWorkerVersion* version,
       scoped_refptr<ServiceWorkerVersion>* data_member,
       int change_flag);
   void UnsetVersionInternal(
@@ skipping 14 matching lines @@
   void Clear();
   void OnStoreFinished(scoped_refptr<ServiceWorkerVersion> version,
                        ServiceWorkerStatusCode status);
 
   const GURL pattern_;
   const GURL script_url_;
   const int64 registration_id_;
   bool is_deleted_;
   bool is_uninstalling_;
   bool should_activate_when_ready_;
+  base::Time last_update_check_;
   scoped_refptr<ServiceWorkerVersion> active_version_;
   scoped_refptr<ServiceWorkerVersion> waiting_version_;
   scoped_refptr<ServiceWorkerVersion> installing_version_;
   ObserverList<Listener> listeners_;
   base::WeakPtr<ServiceWorkerContextCore> context_;
 
   DISALLOW_COPY_AND_ASSIGN(ServiceWorkerRegistration);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_SERVICE_WORKER_SERVICE_WORKER_REGISTRATION_H_