Have ScriptPromiseResolver on the Oilpan heap always.

Source/modules/audio_output_devices/HTMLMediaElementAudioOutputDevice.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/audio_output_devices/HTMLMediaElementAudioOutputDevice.h"
 
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/ScriptState.h"
 #include "core/dom/ExecutionContext.h"
@@ skipping 17 matching lines @@
 {
     m_sinkId = sinkId;
 }
 
 ScriptPromise HTMLMediaElementAudioOutputDevice::setSinkId(ScriptState* scriptState, HTMLMediaElement& element, const String& sinkId)
 {
     WebMediaPlayer* webMediaPlayer = element.webMediaPlayer();
     if (!webMediaPlayer)
         return ScriptPromise::rejectWithDOMException(scriptState, DOMException::create(AbortError, "No media player available"));
 
-    RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     webMediaPlayer->setSinkId(sinkId, new SetSinkIdCallbacks(resolver, element, sinkId));
     return resolver->promise();
 }
 
 const char* HTMLMediaElementAudioOutputDevice::supplementName()
 {
     return "HTMLMediaElementAudioOutputDevice";
 }
 
 HTMLMediaElementAudioOutputDevice& HTMLMediaElementAudioOutputDevice::from(HTMLMediaElement& element)
 {
     HTMLMediaElementAudioOutputDevice* supplement = static_cast<HTMLMediaElementAudioOutputDevice*>(WillBeHeapSupplement<HTMLMediaElement>::from(element, supplementName()));
     if (!supplement) {
         supplement = new HTMLMediaElementAudioOutputDevice();
         provideTo(element, supplementName(), adoptPtrWillBeNoop(supplement));
     }
     return *supplement;
 }
 
 DEFINE_TRACE(HTMLMediaElementAudioOutputDevice)
 {
     WillBeHeapSupplement<HTMLMediaElement>::trace(visitor);
 }
 
 } // namespace blink