Remove TextTrackClient interface to simplify TextTrack code.

Source/core/html/HTMLTrackElement.h

 /*
  * Copyright (C) 2011 Google 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 16 matching lines @@
 #define HTMLTrackElement_h
 
 #include "core/html/HTMLElement.h"
 #include "core/html/track/LoadableTextTrack.h"
 #include "core/html/track/TextTrack.h"
 
 namespace WebCore {
 
 class HTMLMediaElement;
 
-class HTMLTrackElement FINAL : public HTMLElement, public TextTrackClient {
+class HTMLTrackElement FINAL : public HTMLElement {
 public:
     static PassRefPtr<HTMLTrackElement> create(Document&);
 
     const AtomicString& kind();
     void setKind(const AtomicString&);
 
     enum ReadyState { NONE = 0, LOADING = 1, LOADED = 2, TRACK_ERROR = 3 };
     ReadyState readyState();
     void setReadyState(ReadyState);
 
@@ skipping 14 matching lines @@
 
     virtual InsertionNotificationRequest insertedInto(ContainerNode*) OVERRIDE;
 
     virtual void removedFrom(ContainerNode*) OVERRIDE;
     virtual bool isURLAttribute(const Attribute&) const OVERRIDE;
 
     void loadTimerFired(Timer<HTMLTrackElement>*);
 
     HTMLMediaElement* mediaElement() const;
 
-    // TextTrackClient
-    virtual void textTrackModeChanged(TextTrack*) OVERRIDE;
-    virtual void textTrackKindChanged(TextTrack*) OVERRIDE;
-    virtual void textTrackAddCues(TextTrack*, const TextTrackCueList*) OVERRIDE;
-    virtual void textTrackRemoveCues(TextTrack*, const TextTrackCueList*) OVERRIDE;
-    virtual void textTrackAddCue(TextTrack*, PassRefPtr<TextTrackCue>) OVERRIDE;
-    virtual void textTrackRemoveCue(TextTrack*, PassRefPtr<TextTrackCue>) OVERRIDE;
-
     LoadableTextTrack* ensureTrack();
     bool canLoadUrl(const KURL&);
 
     RefPtr<LoadableTextTrack> m_track;
     Timer<HTMLTrackElement> m_loadTimer;
 };
 
 }
 
 #endif