ServiceWorker: Prevent premature garbage collection on ServiceWorkerRegistration

Source/modules/serviceworkers/ServiceWorkerRegistration.cpp

 // 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 "config.h"
 #include "ServiceWorkerRegistration.h"
 
 #include "bindings/core/v8/CallbackPromiseAdapter.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
@@ skipping 129 matching lines @@
     RefPtrWillBeRawPtr<ServiceWorkerRegistration> registration = adoptRefWillBeRefCountedGarbageCollected(new ServiceWorkerRegistration(executionContext, outerRegistration));
     registration->suspendIfNeeded();
     return registration.release();
 }
 
 ServiceWorkerRegistration::ServiceWorkerRegistration(ExecutionContext* executionContext, PassOwnPtr<WebServiceWorkerRegistration> outerRegistration)
     : ActiveDOMObject(executionContext)
     , WebServiceWorkerRegistrationProxy(this)
     , m_outerRegistration(outerRegistration)
     , m_provider(0)
+    , m_stopped(false)
 {
     ASSERT(m_outerRegistration);
     ScriptWrappable::init(this);
 
     if (!executionContext)
         return;
     if (ServiceWorkerContainerClient* client = ServiceWorkerContainerClient::from(executionContext))
         m_provider = client->provider();
     m_outerRegistration->setProxy(this);
 }
 
 void ServiceWorkerRegistration::trace(Visitor* visitor)
 {
     visitor->trace(m_installing);
     visitor->trace(m_waiting);
     visitor->trace(m_active);
     EventTargetWithInlineData::trace(visitor);
 }
 
+bool ServiceWorkerRegistration::hasPendingActivity() const
+{
+    return !m_stopped;
+}
+
+void ServiceWorkerRegistration::stop()
+{
+    if (m_stopped)
+        return;
+    m_stopped = true;
+    m_outerRegistration->proxyStopped();
+}
+
 } // namespace blink