Minor ServiceWorker cleanup. The Registration.Clear method can potentially generated multiple listn…

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/browser/service_worker/service_worker_register_job.h"
 #include "content/browser/service_worker/service_worker_utils.h"
@@ skipping 257 matching lines @@
 
 void ServiceWorkerRegistration::OnDeleteFinished(
     ServiceWorkerStatusCode status) {
   // Intentionally empty completion callback, used to prevent
   // |this| from being deleted until the storage method completes.
 }
 
 void ServiceWorkerRegistration::Clear() {
   context_->storage()->NotifyDoneUninstallingRegistration(this);
 
-  if (installing_version()) {
-    installing_version()->Doom();
-    UnsetVersion(installing_version());
+  ChangedVersionAttributesMask mask;
+  if (installing_version_) {
+    installing_version_->Doom();
+    installing_version_ = NULL;
+    mask.add(ChangedVersionAttributesMask::INSTALLING_VERSION);
   }
-
-  if (waiting_version()) {
-    waiting_version()->Doom();
-    UnsetVersion(waiting_version());
+  if (waiting_version_) {
+    waiting_version_->Doom();
+    waiting_version_ = NULL;
+    mask.add(ChangedVersionAttributesMask::WAITING_VERSION);
   }
-
-  if (active_version()) {
-    active_version()->Doom();
-    UnsetVersion(active_version());
+  if (active_version_) {
+    active_version_->Doom();
+    active_version_->RemoveListener(this);
+    active_version_ = NULL;
+    mask.add(ChangedVersionAttributesMask::ACTIVE_VERSION);
+  }
+  if (mask.changed()) {
+    ServiceWorkerRegistrationInfo info = GetInfo();
+    FOR_EACH_OBSERVER(Listener, listeners_,
+                      OnVersionAttributesChanged(this, mask, info));
   }
 }
 
 void ServiceWorkerRegistration::OnStoreFinished(
     scoped_refptr<ServiceWorkerVersion> version,
     ServiceWorkerStatusCode status) {
   if (!context_)
     return;
   context_->storage()->NotifyDoneInstallingRegistration(
       this, version.get(), status);
 }
 
 }  // namespace content