Have ScriptPromiseResolver on the Oilpan heap always.

Source/modules/presentation/PresentationRequest.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/presentation/PresentationRequest.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptPromise.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
@@ skipping 29 matching lines @@
 bool PresentationRequest::hasPendingActivity() const
 {
     // Prevents garbage collecting of this object when not hold by another
     // object but still has listeners registered.
     return hasEventListeners();
 }
 
 ScriptPromise PresentationRequest::start(ScriptState* scriptState)
 {
     // TODO(mlamouri): migrate from Presentation, see https://crbug.com/510483
-    RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
     return promise;
 }
 
 ScriptPromise PresentationRequest::join(ScriptState* scriptState, const String& id)
 {
     // TODO(mlamouri): migrate from Presentation, see https://crbug.com/510483
-    RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
     return promise;
 }
 
 ScriptPromise PresentationRequest::getAvailability(ScriptState* scriptState)
 {
     // TODO(mlamouri): migrate from Presentation, see https://crbug.com/510483
-    RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
     return promise;
 }
 
 const KURL& PresentationRequest::url() const
 {
     return m_url;
 }
 
 DEFINE_TRACE(PresentationRequest)
 {
     RefCountedGarbageCollectedEventTargetWithInlineData<PresentationRequest>::trace(visitor);
     ActiveDOMObject::trace(visitor);
 }
 
 PresentationRequest::PresentationRequest(ExecutionContext* executionContext, const KURL& url)
     : ActiveDOMObject(executionContext)
     , m_url(url)
 {
 }
 
 } // namespace blink