Have ScriptPromiseResolver on the Oilpan heap always.

Source/core/streams/ReadableStreamReader.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 "core/streams/ReadableStreamReader.h"
 
 #include "bindings/core/v8/ExceptionState.h"
 #include "bindings/core/v8/ScriptPromiseResolver.h"
 #include "bindings/core/v8/V8IteratorResultValue.h"
@@ skipping 34 matching lines @@
 {
     return cancel(scriptState, ScriptValue(scriptState, v8::Undefined(scriptState->isolate())));
 }
 
 ScriptPromise ReadableStreamReader::cancel(ScriptState* scriptState, ScriptValue reason)
 {
     if (isActive())
         return m_stream->cancelInternal(scriptState, reason);
 
     // A method should return a different promise on each call.
-    RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
+    ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
     ScriptPromise promise = resolver->promise();
     resolver->resolve(closed(scriptState).v8Value());
     return promise;
 }
 
 ScriptPromise ReadableStreamReader::read(ScriptState* scriptState)
 {
     if (!isActive()) {
         ASSERT(m_stateAfterRelease == ReadableStream::Closed || m_stateAfterRelease == ReadableStream::Errored);
         if (m_stateAfterRelease == ReadableStream::Closed) {
             // {value: undefined, done: true}
             return ScriptPromise::cast(scriptState, v8IteratorResultDone(scriptState));
         }
         // A method should return a different promise on each call.
-        RefPtrWillBeRawPtr<ScriptPromiseResolver> resolver = ScriptPromiseResolver::create(scriptState);
+        ScriptPromiseResolver* resolver = ScriptPromiseResolver::create(scriptState);
         ScriptPromise promise = resolver->promise();
         resolver->resolve(closed(scriptState).v8Value());
         return promise;
     }
 
     return m_stream->read(scriptState);
 }
 
 void ReadableStreamReader::releaseLock(ExceptionState& es)
 {
@@ skipping 47 matching lines @@
 }
 
 DEFINE_TRACE(ReadableStreamReader)
 {
     visitor->trace(m_stream);
     visitor->trace(m_closed);
     ActiveDOMObject::trace(visitor);
 }
 
 } // namespace blink