Clean up HTMLTrackElement.kind invalid/missing value default handling

third_party/WebKit/Source/core/html/track/TrackBase.h

 /*
  * Copyright (C) 2011 Apple Inc.  All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 45 matching lines @@
     String id() const { return m_id; }
     void setId(const String& id) { m_id = id; }
 
     void setMediaElement(HTMLMediaElement* mediaElement) { m_mediaElement = mediaElement; }
     HTMLMediaElement* mediaElement() const { return m_mediaElement; }
     Node* owner() const;
 
     DECLARE_VIRTUAL_TRACE();
 
 protected:
-    TrackBase(WebMediaPlayer::TrackType, const AtomicString& label, const AtomicString& language, const String& id);
-
-    virtual bool isValidKind(const AtomicString&) const = 0;
-    virtual AtomicString invalidValueDefaultKind() const = 0;
+    TrackBase(WebMediaPlayer::TrackType, const AtomicString& kind, const AtomicString& label, const AtomicString& language, const String& id);
 
 private:
     WebMediaPlayer::TrackId m_trackId;
     WebMediaPlayer::TrackType m_type;
     AtomicString m_kind;
     AtomicString m_label;
     AtomicString m_language;
     String m_id;
     Member<HTMLMediaElement> m_mediaElement;
 };
 
 #define DEFINE_TRACK_TYPE_CASTS(thisType, predicate) \
     DEFINE_TYPE_CASTS(thisType, TrackBase, track, track->type() == predicate, track.type() == predicate)
 
 } // namespace blink
 
 #endif // TrackBase_h