blink: Cleanup class forward declarations

third_party/WebKit/Source/modules/encryptedmedia/HTMLMediaElementEncryptedMedia.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 HTMLMediaElementEncryptedMedia_h
 #define HTMLMediaElementEncryptedMedia_h
 
 #include "core/EventTypeNames.h"
 #include "core/dom/DOMTypedArray.h"
 #include "core/events/EventTarget.h"
 #include "modules/ModulesExport.h"
 #include "platform/Supplementable.h"
 #include "platform/heap/Handle.h"
 #include "public/platform/WebEncryptedMediaTypes.h"
 #include "public/platform/WebMediaPlayerEncryptedMediaClient.h"
 
 namespace blink {
 
-class ExceptionState;
 class HTMLMediaElement;
 class MediaKeys;
 class ScriptPromise;
 class ScriptState;
 class WebContentDecryptionModule;
 class WebMediaPlayer;
 
 class MODULES_EXPORT HTMLMediaElementEncryptedMedia final
     : public GarbageCollectedFinalized<HTMLMediaElementEncryptedMedia>,
       public Supplement<HTMLMediaElement>,
@@ skipping 41 matching lines @@
   // - attaching media keys, which shall have a boolean value
   bool m_isWaitingForKey;
   bool m_isAttachingMediaKeys;
 
   Member<MediaKeys> m_mediaKeys;
 };
 
 }  // namespace blink
 
 #endif