Have ScriptPromiseResolver on the Oilpan heap always.

Source/modules/background_sync/SyncCallbacks.h

 // 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.
 
 #ifndef SyncCallbacks_h
 #define SyncCallbacks_h
 
 #include "platform/heap/Handle.h"
 #include "public/platform/WebCallbacks.h"
 #include "public/platform/modules/background_sync/WebSyncProvider.h"
@@ skipping 10 matching lines @@
 struct WebSyncRegistration;
 class WebString;
 
 // SyncRegistrationCallbacks is an implementation of WebSyncRegistrationCallbacks
 // that will resolve the underlying promise depending on the result passed to
 // the callback. It takes a ServiceWorkerRegistration in its constructor and
 // will pass it to the SyncRegistration.
 class SyncRegistrationCallbacks final : public WebSyncRegistrationCallbacks {
     WTF_MAKE_NONCOPYABLE(SyncRegistrationCallbacks);
 public:
-    SyncRegistrationCallbacks(PassRefPtrWillBeRawPtr<ScriptPromiseResolver>, ServiceWorkerRegistration*);
+    SyncRegistrationCallbacks(ScriptPromiseResolver*, ServiceWorkerRegistration*);
     ~SyncRegistrationCallbacks() override;
 
     void onSuccess(WebSyncRegistration*) override;
     void onError(WebSyncError*) override;
 
 private:
-    RefPtrWillBePersistent<ScriptPromiseResolver> m_resolver;
+    Persistent<ScriptPromiseResolver> m_resolver;
     Persistent<ServiceWorkerRegistration> m_serviceWorkerRegistration;
 };
 
 // SyncUnregistrationCallbacks is an implementation of
 // WebSyncUnregistrationCallbacks that will resolve the underlying promise
 // depending on the result passed to the callback. It takes a
 // ServiceWorkerRegistration in its constructor and will pass it to the
 // SyncProvider.
 class SyncUnregistrationCallbacks final : public WebSyncUnregistrationCallbacks {
     WTF_MAKE_NONCOPYABLE(SyncUnregistrationCallbacks);
 public:
-    SyncUnregistrationCallbacks(PassRefPtrWillBeRawPtr<ScriptPromiseResolver>, ServiceWorkerRegistration*);
+    SyncUnregistrationCallbacks(ScriptPromiseResolver*, ServiceWorkerRegistration*);
     ~SyncUnregistrationCallbacks() override;
 
     void onSuccess(bool*) override;
     void onError(WebSyncError*) override;
 
 private:
-    RefPtrWillBePersistent<ScriptPromiseResolver> m_resolver;
+    Persistent<ScriptPromiseResolver> m_resolver;
     Persistent<ServiceWorkerRegistration> m_serviceWorkerRegistration;
 };
 
 // SyncGetRegistrationsCallbacks is an implementation of WebSyncGetRegistrationsCallbacks
 // that will resolve the underlying promise depending on the result passed to
 // the callback. It takes a ServiceWorkerRegistration in its constructor and
 // will pass it to the SyncRegistration.
 class SyncGetRegistrationsCallbacks final : public WebSyncGetRegistrationsCallbacks {
     WTF_MAKE_NONCOPYABLE(SyncGetRegistrationsCallbacks);
 public:
-    SyncGetRegistrationsCallbacks(PassRefPtrWillBeRawPtr<ScriptPromiseResolver>, ServiceWorkerRegistration*);
+    SyncGetRegistrationsCallbacks(ScriptPromiseResolver*, ServiceWorkerRegistration*);
     ~SyncGetRegistrationsCallbacks() override;
 
     void onSuccess(WebVector<WebSyncRegistration*>*) override;
     void onError(WebSyncError*) override;
 
 private:
-    RefPtrWillBePersistent<ScriptPromiseResolver> m_resolver;
+    Persistent<ScriptPromiseResolver> m_resolver;
     Persistent<ServiceWorkerRegistration> m_serviceWorkerRegistration;
 };
 
 // SyncGetPermissionStatusCallbacks is an implementation of
 // WebSyncGetPermissionStatusCallbacks that will resolve the underlying promise
 // depending on the permission status passed to the callback.
 class SyncGetPermissionStatusCallbacks final : public WebSyncGetPermissionStatusCallbacks {
     WTF_MAKE_NONCOPYABLE(SyncGetPermissionStatusCallbacks);
 public:
-    SyncGetPermissionStatusCallbacks(PassRefPtrWillBeRawPtr<ScriptPromiseResolver>, ServiceWorkerRegistration*);
+    SyncGetPermissionStatusCallbacks(ScriptPromiseResolver*, ServiceWorkerRegistration*);
     ~SyncGetPermissionStatusCallbacks() override;
 
     void onSuccess(WebSyncPermissionStatus*) override;
     void onError(WebSyncError*) override;
 
 private:
     static String permissionString(WebSyncPermissionStatus);
-    RefPtrWillBePersistent<ScriptPromiseResolver> m_resolver;
+
+    Persistent<ScriptPromiseResolver> m_resolver;
     Persistent<ServiceWorkerRegistration> m_serviceWorkerRegistration;
 };
 
 } // namespace blink
 
 #endif // SyncCallbacks_h