Add a pre-finalizer to PromiseRejectionEvent

third_party/WebKit/Source/core/events/PromiseRejectionEvent.h

Index: third_party/WebKit/Source/core/events/PromiseRejectionEvent.h
diff --git a/third_party/WebKit/Source/core/events/PromiseRejectionEvent.h b/third_party/WebKit/Source/core/events/PromiseRejectionEvent.h
index 53a854b8c3735690b006fd9ae2792d91ebc9b779..ba47ddaaab9aea5afd1b3502708206b735f05d6f 100644
--- a/third_party/WebKit/Source/core/events/PromiseRejectionEvent.h
+++ b/third_party/WebKit/Source/core/events/PromiseRejectionEvent.h
@@ -18,6 +18,7 @@ namespace blink {
 
 class CORE_EXPORT PromiseRejectionEvent final : public Event {
     DEFINE_WRAPPERTYPEINFO();
+    USING_PRE_FINALIZER(PromiseRejectionEvent, dispose);
 public:
     static PromiseRejectionEvent* create()
     {
@@ -47,6 +48,7 @@ private:
     PromiseRejectionEvent();
     PromiseRejectionEvent(ScriptState*, const AtomicString&, const PromiseRejectionEventInit&);
     ~PromiseRejectionEvent() override;
+    void dispose();
 
     RefPtr<ScriptState> m_scriptState;
     ScopedPersistent<v8::Value> m_promise;