Oilpan: keep StashedPortCollection always on the heap.

Source/modules/serviceworkers/StashedPortCollection.cpp

 // Copyright 2015 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 "modules/serviceworkers/StashedPortCollection.h"
 
 #include "bindings/core/v8/SerializedScriptValueFactory.h"
 #include "modules/EventTargetModules.h"
 #include "modules/serviceworkers/ServiceWorkerGlobalScopeClient.h"
 #include "modules/serviceworkers/StashedMessagePort.h"
 #include "public/platform/WebString.h"
 
 namespace blink {
 
-PassRefPtrWillBeRawPtr<StashedPortCollection> StashedPortCollection::create(ExecutionContext* context)
+StashedPortCollection* StashedPortCollection::create(ExecutionContext* context)
 {
-    return adoptRefWillBeNoop(new StashedPortCollection(context));
+    return new StashedPortCollection(context);
 }
 
 StashedPortCollection::StashedPortCollection(ExecutionContext* context)
     : ContextLifecycleObserver(context)
 {
 }
 
 StashedPortCollection::~StashedPortCollection()
 {
 }
@@ skipping 18 matching lines @@
 }
 
 ExecutionContext* StashedPortCollection::executionContext() const
 {
     return ContextLifecycleObserver::executionContext();
 }
 
 DEFINE_TRACE(StashedPortCollection)
 {
     visitor->trace(m_ports);
-    EventTargetWithInlineData::trace(visitor);
+    RefCountedGarbageCollectedEventTargetWithInlineData::trace(visitor);
     ContextLifecycleObserver::trace(visitor);
 }
 
 } // namespace blink
-