ServiceWorker: Bypass resolving a promise when ExecutionContext is gone

Source/modules/push_messaging/PushError.h

 // Copyright 2014 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 PushError_h
 #define PushError_h
 
 #include "core/dom/DOMException.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebPushError.h"
 
 namespace blink {
 
 class ScriptPromiseResolver;
 
 class PushError {
     WTF_MAKE_NONCOPYABLE(PushError);
 public:
     // For CallbackPromiseAdapter.
     typedef blink::WebPushError WebType;
     static PassRefPtrWillBeRawPtr<DOMException> from(ScriptPromiseResolver*, WebType* webErrorRaw);
+    static void dispose(WebType* webErrorRaw);
 
 private:
     PushError() WTF_DELETED_FUNCTION;
 };
 
 } // namespace blink
 
 #endif // PushError_h