Fix crash in ServiceWorkerRegistrationHandle

content/browser/service_worker/service_worker_registration_handle.cc

 // 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.
 
 #include "content/browser/service_worker/service_worker_registration_handle.h"
 
 #include "content/browser/service_worker/service_worker_context_core.h"
 #include "content/browser/service_worker/service_worker_dispatcher_host.h"
 #include "content/browser/service_worker/service_worker_handle.h"
 #include "content/common/service_worker/service_worker_messages.h"
@@ skipping 15 matching lines @@
       ref_count_(1),
       registration_(registration) {
   DCHECK(registration_);
   SetVersionAttributes(registration->installing_version(),
                        registration->waiting_version(),
                        registration->active_version());
   registration_->AddListener(this);
 }
 
 ServiceWorkerRegistrationHandle::~ServiceWorkerRegistrationHandle() {
+  DCHECK(registration_);
   registration_->RemoveListener(this);
 }
 
 void ServiceWorkerRegistrationHandle::IncrementRefCount() {
   DCHECK_GT(ref_count_, 0);
   ++ref_count_;
 }
 
 void ServiceWorkerRegistrationHandle::DecrementRefCount() {
   DCHECK_GT(ref_count_, 0);
   --ref_count_;
 }
 
 void ServiceWorkerRegistrationHandle::OnVersionAttributesChanged(
     ServiceWorkerRegistration* registration,
     ChangedVersionAttributesMask changed_mask,
     const ServiceWorkerRegistrationInfo& info) {
   DCHECK_EQ(registration->id(), registration_->id());
   SetVersionAttributes(registration->installing_version(),
                        registration->waiting_version(),
                        registration->active_version());
 }
 
 void ServiceWorkerRegistrationHandle::OnRegistrationFailed(
     ServiceWorkerRegistration* registration) {
   DCHECK_EQ(registration->id(), registration_->id());
   ClearVersionAttributes();
-  registration_->RemoveListener(this);
-  registration_ = NULL;
 }
 
 void ServiceWorkerRegistrationHandle::SetVersionAttributes(
     ServiceWorkerVersion* installing_version,
     ServiceWorkerVersion* waiting_version,
     ServiceWorkerVersion* active_version) {
   ChangedVersionAttributesMask mask;
 
   if (installing_version != installing_version_) {
     installing_version_ = installing_version;
@@ skipping 47 matching lines @@
                                     kDocumentMainThreadId,
                                     provider_id_,
                                     version);
     info = handle->GetObjectInfo();
     dispatcher_host_->RegisterServiceWorkerHandle(handle.Pass());
   }
   return info;
 }
 
 }  // namespace content