Simplify use of ContentDecryptionModuleResult with promises

Source/modules/encryptedmedia/SimpleContentDecryptionModuleResult.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 SimpleContentDecryptionModuleResult_h
-#define SimpleContentDecryptionModuleResult_h
-
-#include "core/dom/ExceptionCode.h"
-#include "platform/ContentDecryptionModuleResult.h"
-#include "wtf/Forward.h"
-
-namespace blink {
-
-class ScriptPromise;
-class ScriptPromiseResolver;
-class ScriptState;
-class WebString;
-
-ExceptionCode WebCdmExceptionToExceptionCode(WebContentDecryptionModuleException);
-
-// This class wraps the promise resolver and is passed (indirectly) to Chromium
-// to fullfill the promise. This implementation of complete() will resolve the
-// promise with undefined, while completeWithError() reject the promise with an
-// exception. completeWithSession() is not expected to be called, and will
-// reject the promise.
-class SimpleContentDecryptionModuleResult : public ContentDecryptionModuleResult {
-public:
-    explicit SimpleContentDecryptionModuleResult(ScriptState*);
-    virtual ~SimpleContentDecryptionModuleResult();
-
-    // ContentDecryptionModuleResult implementation.
-    virtual void complete() override;
-    virtual void completeWithSession(WebContentDecryptionModuleResult::SessionStatus) override;
-    virtual void completeWithError(WebContentDecryptionModuleException, unsigned long systemCode, const WebString&) override;
-
-    // It is only valid to call this before completion.
-    ScriptPromise promise();
-
-private:
-    // Reject the promise with a DOMException.
-    void completeWithDOMException(ExceptionCode, const String& errorMessage);
-
-    RefPtr<ScriptPromiseResolver> m_resolver;
-};
-
-} // namespace blink
-
-#endif // SimpleContentDecryptionModuleResult_h