EME: Improve promise lifetime

third_party/WebKit/Source/modules/encryptedmedia/SimpleContentDecryptionModuleResultPromise.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 SimpleContentDecryptionModuleResultPromise_h
-#define SimpleContentDecryptionModuleResultPromise_h
-
-#include "modules/encryptedmedia/ContentDecryptionModuleResultPromise.h"
-
-namespace blink {
-
-// This class creates a simple ContentDecryptionModuleResultPromise where the
-// implementation of complete() will resolve the promise with void. All other
-// complete() methods are not expected to be called (and will reject the
-// promise).
-class SimpleContentDecryptionModuleResultPromise
-    : public ContentDecryptionModuleResultPromise {
- public:
-  explicit SimpleContentDecryptionModuleResultPromise(ScriptState*);
-  ~SimpleContentDecryptionModuleResultPromise() override;
-
-  // ContentDecryptionModuleResultPromise implementation.
-  void complete() override;
-};
-
-}  // namespace blink
-
-#endif  // SimpleContentDecryptionModuleResultPromise_h