Introduce ServiceWorkerHandle for tracking WebServiceWorkerImpl reference

content/browser/service_worker/service_worker_registration.cc

 // 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.
 
 #include "content/browser/service_worker/service_worker_registration.h"
 
 #include "content/browser/service_worker/service_worker_context_core.h"
 #include "content/browser/service_worker/service_worker_info.h"
 #include "content/public/browser/browser_thread.h"
 
 namespace content {
 
 ServiceWorkerRegistration::ServiceWorkerRegistration(
     const GURL& pattern,
     const GURL& script_url,
     int64 registration_id,
     base::WeakPtr<ServiceWorkerContextCore> context)
     : pattern_(pattern),
       script_url_(script_url),
       registration_id_(registration_id),
       is_shutdown_(false),
       context_(context) {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   DCHECK(context_);
   context_->AddLiveRegistration(this);
 }
 
 ServiceWorkerRegistration::~ServiceWorkerRegistration() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
-  DCHECK(is_shutdown_);
-}
-
-void ServiceWorkerRegistration::Shutdown() {
-  DCHECK(!is_shutdown_);
-  if (active_version_)
-    active_version_->Shutdown();
-  active_version_ = NULL;
-  if (pending_version_)
-    pending_version_->Shutdown();
-  pending_version_ = NULL;
-  is_shutdown_ = true;
   if (context_)
     context_->RemoveLiveRegistration(registration_id_);
 }
 
 ServiceWorkerRegistrationInfo ServiceWorkerRegistration::GetInfo() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
   return ServiceWorkerRegistrationInfo(
       script_url(),
       pattern(),
       active_version_ ? active_version_->GetInfo() : ServiceWorkerVersionInfo(),
       pending_version_ ? pending_version_->GetInfo()
                        : ServiceWorkerVersionInfo());
 }
 
 ServiceWorkerVersion* ServiceWorkerRegistration::GetNewestVersion() {
   if (active_version())
     return active_version();
   return pending_version();
 }
 
 void ServiceWorkerRegistration::ActivatePendingVersion() {
   active_version_->SetStatus(ServiceWorkerVersion::DEACTIVATED);
-  active_version_->Shutdown();
   active_version_ = pending_version_;
   // TODO(kinuko): This should be set to ACTIVATING until activation finishes.
   active_version_->SetStatus(ServiceWorkerVersion::ACTIVE);
   pending_version_ = NULL;
 }
 
 }  // namespace content