Only dispose proxy-less WebServiceWorkerRegistration objects.

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 72 matching lines @@
     return getOrCreate(executionContext, registration);
 }
 
 ServiceWorkerRegistration* ServiceWorkerRegistration::take(ScriptPromiseResolver* resolver, WebType* registration)
 {
     return from(resolver->scriptState()->executionContext(), registration);
 }
 
 void ServiceWorkerRegistration::dispose(WebType* registration)
 {
-    delete registration;
+    if (registration && !registration->proxy())
+        delete registration;
 }
 
 String ServiceWorkerRegistration::scope() const
 {
     return m_outerRegistration->scope().string();
 }
 
 ScriptPromise ServiceWorkerRegistration::unregister(ScriptState* scriptState)
 {
     RefPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
@@ skipping 67 matching lines @@
 
 void ServiceWorkerRegistration::stop()
 {
     if (m_stopped)
         return;
     m_stopped = true;
     m_outerRegistration->proxyStopped();
 }
 
 } // namespace blink